Chan Chung-sing graduated from the Kwangtung Law College in 1919. In 1920 he went to France, where he received his degrees of Licencie of Law and Doctor of Political Science and Economics from Universite de Paris, 1925.
From 1925 to 1928 Chan Chung-sing was a secretary of the International Labor Office in the Asiatic Inquiry Department. He was a constant contributor to many European periodicals. In 1928 Chan Chung-sing returned to China with Albert Thomas. In the period from June 1930 to July 1934 he held the post of director of the International Labor Office. Later he worked as a secretary of the International Labor Office in Geneva.