The studies of Modem Chinese classics influenced by the academic trends in the early Republic of China were different from the traditional academic points of view. In the modem period, "Zuo zhuan" has been regarded as the historiography. Therefore, the fundamental values of "Zuo zhuan" which was regarded as Chinese classics by traditional academic were lost based on this point of view. After both Liu Shi-pei and Zhang Tai Yan's studies in the late Qing Dynasty, Liu Zhenghao continued to make his research on traditional classics. He advocated that the content and the truth of "Zuo zhuan" were popular in the Zhou, Qin and Western Han and Eastern Han Dynasties. Also, he proved the authenticity of "Zuo zhuan". In addition, he proactively made a clear description of "Chunqiu" which was originally a historiography and later became a classic. Besides, Liu Zhenghao addressed that "Zuo zhuan" is an integration of historiography and classics. His argument released the other scholars' query on “Zuo Zhuan". In this paper, Liu Zhenghao's inheritance, research papers and assertion will be discussed and interpreted.