Sources close to the leadership say 10 main candidates are vying for seven seats on the party's next Politburo Standing Committee, the peak decision-making body which will steer the world's second-largest economy for the next five years.
Only two candidates are considered certainties going into the party's 18th congress, which starts on Thursday: leader-in-waiting Xi Jinping and his designated deputy, Li Keqiang, who are set to be installed as president and premier March 2013.
Of the remaining eight contenders, only one has the reputation as a political reformer and only one is a woman.
Following are short biographies of the candidates, including their reform credentials and possible portfolio responsibilities.
A combination picture shows the 10 main candidates sources said are vying for seven seats on China's ruling Communist Party party's next Politburo Standing Committee. Top row from left to right: Xi Jinping, Li Keqiang, Zhang Dejiang, Wang Qishan, and Li Yuanchao. Bottom row from left to right: Zhang Gaoli, Wang Yang, Liu Yandong, Liu Yunshan, and Yu Zhengsheng. Reuters photo
Reform credentials: Considered a cautious reformer, having spent time in top positions in Fujian and Zhejiang provinces, both at the forefront of China's economic reforms.
Xi Jinping, 59, is China's vice president and President Hu Jintao's anointed successor. He will take over as Communist Party boss at the congress and then as head of state in March.
Xi belongs to the party's "princeling" generation, the offspring of communist revolutionaries. His father, former vice premier Xi Zhongxun, fought alongside Mao Zedong in the Chinese civil war. Xi watched his father purged and later, during the Cultural Revolution, spent years in the hardscrabble countryside before making his way to university and then to power.
Married to a famous singer, Xi has crafted a low-key and sometimes blunt political style. He has complained that officials' speeches and writings are clogged with party jargon and has demanded more plain speaking.
Chinese vice president Xi Jinping at the Great Hall of the People in Beijing. AP Photo
Xi went to work in the poor northwest Chinese countryside as a "sent-down youth" during the chaos of the 1966-76 Cultural Revolution, and became a rural commune official. He went on to study chemical engineering at Tsinghua University in Beijing and later gained a doctorate in Marxist theory from Tsinghua.
A native of the poor, inland province of Shaanxi, Xi was promoted to governor of southeastern Fujian province in 1999 and became party boss in neighbouring Zhejiang province in 2003.
In 2007, the tall, portly Xi secured the top job in China's commercial capital, Shanghai, when his predecessor was caught up in a huge corruption case. Later that year he was promoted to the party's standing committee.
Reform credentials: Seen as another cautious reformer due to his relatively liberal university experiences.
Vice Premier Li Keqiang, 57, is the man tipped to be China's next premier, taking over from Wen Jiabao.
His ascent will mark an extraordinary rise for a man who as a youth was sent to toil in the countryside during Mao's Cultural Revolution.
He was born in Anhui province in 1955, son of a local rural official. Li worked on a commune that was one of the first places to quietly revive private bonuses in farming in the late 1970s. Short history of China's Communist Party
By the time he left Anhui, Li was a Communist Party member and secretary of his production brigade.
China's vice premier Li Keqiang attends a meeting with European commission president Jose Manuel Barroso in Brussels. Reuters file photo
He studied law at the elite Peking University, which was among the first Chinese schools to resume teaching law after the Cultural Revolution. He worked to master English and co-translated The Due Process of Law by Lord Denning, the famed English jurist.
In 1980, Li, then in the official student union, endorsed controversial campus elections. Party conservatives were aghast, but Li, already a prudent political player, stayed out of the controversial vote.
He climbed the party ranks and in 1983 joined the Communist Youth League's central secretariat, headed then by Hu Jintao.
Li later served in challenging party chief posts in Liaoning, a frigid northeastern rustbelt province, and rural Henan province. He was named to the powerful nine-member standing committee in 2007.
Reform Credentials: A financial reformer and problem solver with deep experience tackling tricky economic and political problems.
Wang Qishan, 64, is the most junior of four vice premiers and an ex-mayor of Beijing.
But he has a keen grasp of complex economic issues and is the only likely member of the Standing Committee to have been chief executive of a corporation, leading the state-owned China Construction Bank from 1994 to 1997.
As such, he may take a leading role in shaping economic policy, including trade and foreign investment.
Wang Qishan, China's vice premier, attends a news conference after meeting with Brazil's Vice President Michel Temer at the Itamaraty Palace in Brasilia. Reuters file photo
Wang is an experienced negotiator who has led finance and trade negotiations as well as the Strategic and Economic Dialogue with the United States. He is a favourite of foreign investors and has long been seen as a problem solver, sorting out a debt crisis in Guangdong province where he was vice governor in the late 1990s and replacing the sacked Beijing mayor after a cover-up of the deadly SARS virus in 2003.
Wang is also a princeling, son-in-law of a former vice premier and ex-standing committee member, Yao Yilin. His possible portfolio could be chairman of the National People's Congress (China's rubber-stamp parliament), head of parliament's advisory body, executive vice premier (responsible for economic issues) or the party's top anti-corruption official.
Reform credentials: A conservative who has kept domestic media on a tight leash.
Liu Yunshan attends the closing ceremony of the NPC at the Great Hall of the People in Beijing. Reuters file photo
Liu Yunshan, 65, may take over the propaganda and ideology portfolio for the Standing Committee.
He has a background in media, once working as a reporter for state-run news agency Xinhua in Inner Mongolia, where he later served in party and propaganda roles before shifting to Beijing.
As minister of the party's Propaganda Department since 2002, Liu has also sought to control China's Internet, which has more than 500 million users. He has been a member of the wider Politburo for two five-year terms ending this year.
Liu has not worked directly for the Communist Youth League, but is aligned to it through his lengthy career in an inland, poor province, long ties to the party's propaganda system and close relationship with Hu Jintao.
Reform Credentials: A reformer who has courted foreign investment and studied in the United States.
Li Yuanchao , 61, oversees the appointment of senior party, government, military and state-owned enterprise officials as head of the party's powerful organisation department. On the Standing Committee, he could head the fight against corruption.
Li Yuanchao attends the closing ceremony of the NPC at the Great Hall of the People in Beijing. Reuters file photo
Li, whose father was a vice-mayor of Shanghai, has risen far since his parents were persecuted and he was a humble farm hand during the Cultural Revolution.
Politically astute, Li can navigate between interest groups, from Hu's Youth League power base to the princelings.
As party chief in his native province, Jiangsu, from 2002 to 2007, Li oversaw a rapid rise in personal incomes and economic development, attracting foreign investment from global industrial leaders such as Ford, Samsung and Caterpillar.
He earned mathematics and economics degrees from two of China's best universities and a doctorate in law. He also spent time at Harvard University's Kennedy School of Government in the United States.
Reform credentials: A conservative trained in North Korea.
Zhang Dejiang attends the Chongqing municipality's communist party Congress in Chongqing municipality. Reuters file photo
Zhang Dejiang, 65, saw his chances of promotion boosted this year when he was chosen to replace disgraced politician Bo Xilai as Chongqing party boss. He also serves as vice premier in charge of industry, though his record has been tarnished by the downfall of the railway minister last year for corruption.
Zhang is close to former president Jiang Zemin who still wields some influence. He studied economics at Kim Il-sung University in North Korea and is a native of northeast China.
On his watch as party chief of Guangdong, the southern province maintained its position as a powerhouse of China's economic growth, even as it struggled with energy shortages, corruption-fuelled unrest and the 2003 SARS epidemic.
Reform credentials: A financial reformer with experience in more developed parts of China.
Zhang Gaoli attends the closing ceremony of the NPC in Beijing. Reuters file photo
Zhang Gaoli, 65, party chief of the northern port city of Tianjin and a Politburo member since 2007, is seen as a Jiang Zemin ally but also acceptable to President Hu, who has visited Tianjin three times since 2008. Zhang is an advocate of greater foreign investment and he introduced financial reforms in a bid to turn the city into a financial centre in northern China. Understanding China's 18th Communist Party Congress
He was sent to clean up Tianjin, which was hit by a string of corruption scandals implicating his predecessor and the former top adviser to the city's lawmaking body. The adviser committed suicide shortly after Zhang's arrival.
A native of southeastern Fujian province, Zhang trained as an economist. He also served as party chief and governor of eastern Shandong province and as Guangdong vice governor.
Zhang is low-key with a down-to-earth work style, and not much is known about his specific interests and aspirations. But with his leadership experience in more economically advanced cities and provinces, including party secretary of the showcase manufacturing and export-driven city of Shenzhen, he could be named executive vice premier.
Reform credentials: Seen by many in the West as a beacon of political reform.
Wang Yang attends the opening ceremony of the CPPCC at the Great Hall of the People in Beijing. Reuters file photo
Wang Yang, 57, is party chief of the export dependent economic hub of Guangdong province. He was not included in a list of preferred Standing Committee candidates drawn up by Xi, Hu and Hu's predecessor, Jiang Zemin, according to sources close to the leadership, but is firmly in the running.
Born into a poor rural family in eastern Anhui province, Wang dropped out of high school and went to work in a food factory at age 17 to help support his family after his father died. These experiences may have shaped his desire for more socially inclusive policies, including his "Happy Guangdong" model of development designed to improve quality of life.
Concerned about the social impact of three decades of blistering development, he lobbied for social and political reform. However, this approach has drawn criticism from party conservatives and Wang has more recently adopted the party's more familiar method of control and punishment to keep order.
Reform credentials: Relatively low-key but considered a cautious reformer.
Yu Zhengsheng attends a meeting at the World Expo site in Shanghai. Reuters file photo
Yu Zhengsheng, 67, is party boss in China's financial hub and most cosmopolitan city, Shanghai.
His impeccable Communist pedigree made him a rising star in the mid-1980s until his brother, an intelligence official, defected to the United States. His close ties with Deng Pufang, the eldest son of late paramount leader Deng Xiaoping, spared him the full political repercussions but he was taken off the fast track.
Yu bided his time in ministerial ranks until bouncing back, joining the Politburo in 2002. However, the princeling's age would require him to retire in 2017 after one term.
Reform credentials: Uncertain.
Liu Yandong, who turns 67 this month, is the only woman given a serious chance to join the Standing Committee but is considered a dark horse. She is a princeling also tied to President Hu's Youth League faction.
Liu Yandong is seen during an official working visit in Bern, Switzerland. Reuters file photo
If promoted, she could head up parliament's advisory body, but her age would also force her to retire after only one term.
Her bigger challenge is that no woman has made it into the Standing Committee since 1949. Not even Jiang Qing, the widow of late Chairman Mao Zedong, made it that far.
Liu, daughter of a former vice-minister of agriculture, is currently the only woman in the 25-member Politburo, a minority in China's male-dominated political culture. She has been on the wider Politburo since 2007 as one of five state councillors, a rank senior to a cabinet minister but junior to a vice-premier.
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