Kwan Sung-sing was born in Weihaiwei on August 29, 1892. When he attended the Lingnan school (嶺南學校), he was heavily influenced by the school chancellor Chung Jung-hua (), who was a member of the revolutionary Tongmenghui. He cut off his braids--a sign of rebellion under the Qing regime-- before the Republic of China was established. As a result, in 1907, Kwan’s father, Dr. King Yin Kwan (), had to entrust his friend Wu Tingfang to take Kwan to study in the United States.