He completed his Chinese education at home. Then hee went to England where he attended Oxford University and the Inner Temple in London, being called to the English Bar in 1916 and receiving his Master of Arts degree in 1915 and also studied in France for one year.
He practised law at Canton, Hongkong and Shanghai and for a time was lecturer at the Comparative Law School at Shanghai. Also Mr. Loo was departmental chief in the Ministry of Foreign Affairs in 1919 and adviser to the Civil Governor of Kwangtung in 1920.
Then he became divisional chief justice of the' supreme court of Canton Constitutional Government in 1921 and , above all, president, Shanghai Provisional Court in 1927-1928. Mr Loo worked as legal practitioner in Shanghai, since 1930