Historical writings in 20th century China witnessed several major changes. These changes caused historians to form different schools in different time periods. In the first half of the 20th century, for instance, there appeared three schools: the scientists, the traditionalists, and the Marxists. Or, from a different perspective, one found the antithesis of the “Historical Source School” and the “Historical Explanation School.” There were also a great deal of exchange and interactions among these schools. Focusing on the early career of Qian Mu, this article examines Qian’s association with the scientific historians, or the leading figures of the “Historical Source School.” The author contends that during the 1920s and the early 1930s, Qian basically adopted the “scientific” approach to the study of history, applying textual criticism to historical sources. It was largely due to the increasing threat of Japan’s invasion in China in the late 1930s that he began to embark on a different career path, which was characterized by and well known for its emphasis on the spirit of Chinese culture and the value of historical narratives.