Lee Tso-yu graduated from the department of political science and economics of Waseda University in Japan.
Upon returning to China in 1908, Mr. Lee became an instructor at the Law School of Hubei. Than he occupied such positions as secretary in the Civil Affairs Department of Zhejiang in 1911, presiding judge of the Peking High Court in 1912, judge of the Supreme Court in 1914.
In recognition of his meritorious services he was promoted presiding judge of the Supreme Court and concurrently member of the Disciplinary Commission of Judicial Officials and instructor of law at the Law Institute in Peking in 1918. In 1921 he went to England, Germany, and other European countries to study judicial administration and investigate economic and financial conditions.
Upon returning to China Lee Tso-yu resigned all governmental positions and became an attorney-at-law in Shanghai in 1922, when he initiated a movement for the rendition of the Shanghai Mixed Court. Mr. Lee served as a Chairman of the Shanghai Bar Association and member of the Standing Committee of the Chinese Ratepayers Association in Shanghai. Then he was appointed member of the Fujian Provincial Government and concurrently Commissioner of Civil Affairs of Fujian in 1934.