was elected an honorary member of the Grotius Society of London, a rare distinction for a Chinese. While reading in London he wrote a book on "Rules of Private International Law Determining Capacity to Contract,” which was described by the International Law Notes of London as "a learned and most clear-headed piece of work.” He returned to China in 1917 and was admitted to the Hongkong Bar. He went to Peking towards the end of 1917. At first was attached to the Ministry of Justice and in 1918 was appointed Chief Compiler of the Law Codification Commission. In 1919 he was appointed Judge of the Supreme Court. In January 1920 Dr. Ch'eng was decorated by the Fourth Order of Chiaho and in the same month appointed Standing Examiner of the Final Examination for Judicial Officials. In September 1920 Dr. Cheng was transferred back to the Law Codification Commission. Since his arrival in Peking he has translated a number of works of Chinese legal literature into English, among which may be mentioned the “Supreme Court decisions" "High Prize Court Judgments,” “Draft Code of Criminal Procedure,” and "Supreme Court Regulations." He has brought out an English version to the draft civil code. Dr. Cheng was elected a member of the International Law Association of London. In September 1921 Dr. Ch'eng was appointed Legal Expert to the Chinese Delegation to the Pacific Conference. In June 1922 he was again appointed Chief Compiler of the Law Codification Commission which position he resigned in November 1923.
