Beijing backed a UN investigation to "find out the truth as soon as possible", he said.
Wang made the comments as the West mulled possible military action against President Bashar al-Assad's regime.
Britain on Monday said the West could act even without full UN Security Council backing after last week's alleged gas attack which the Syrian opposition said killed hundreds of civilians.
"China has paid high attention to the reports that chemical weapons have been used in Syria," Wang said.
"China's view is that we will firmly oppose anyone who uses chemical weapons."
China, one of five veto-wielding permanent council members, has previously attempted to block moves leading to military action in overseas conflict.
Beijing says it opposes intervention in other countries' internal affairs.