Despite being famous for his work of researching Chinese ancient history, Ku Chieh-kang always laid stress on the activities of academic exploration which had to go out the den and stride towards the fields, and he did practice what he emphasized in his academic life. During 1918 to 1945, he joined the activities of investigation or the trips with the characteristics of investigation at least sixty-six times; especially, between the autumn of 1929 when he went back to Beijing from Guangzhou to take up a post at the department of history of Yanching University and the eve of July 7th Incident of 1937 when he fled to western–north China to keep away from the battle, his career of academic exploration climaxed in the eight years. He personally participated in investigative activities twenty times in total in that period, that is, he went to the fields to do research two point five times a year on average. During the period, the focus of his career of academic exploration had transferred from folk research to the investigation of antiquities and frontier history and geography. This paper is aimed at researching the activities of investigation of antiquities in Ku Chieh-kang’s career of academic exploration. Besides carefully researching the motive, process, and concrete exploratory details of Ku’s investigative activities of antiquities, I am going to elaborate and evaluate his achievements and contribution from the following five aspects: first, the examination and collection of antiquities and bibliographies; second, the display and announcement of investigative results; third, to consciously promote the investigation of antiquities to be a professional course; fourth, to awake the society’s respect for antiquities; five, to verify by classics, histories, and ancient books.