The team has increased this week from about 30 Organization for the Prohibition of Chemical Weapons experts and UN support staff to 60, said a statement released as the OPCW celebrated winning the Nobel Peace Prize.
The team "has made good progress in verifying the information submitted" by the Syrian government.
"At the end of the first 10 days of operations on the ground the verification teams have inspected three sites and plans are underway for further site visits," said the statement.
The OPCW was sent to Syria after a chemical weapons attack near Damascus in August sparked an international crisis that led to a US threat of a military strike.
The crisis was defused by a UN Security Council backed disarmament plan drawn up by Russia and the United States and accepted by Syria's President Bashar al-Assad.