The purpose of this study was to identify the epistemological reasons for lack of science in ancient China. The study reveals a striking contrast between China and the West in terms of epistemologies concerning scientific development. In the beginning, the term “science” is defined through some illustrations which can help illuminate its essential features. Then, the study distinguishes the differences between Chinese and Western epistemologies about scientific development. The differences lie mainly in four aspects—distinct patterns of research methodology, reasoning and truth-seeking, and dissimilar understanding of the relationship between man and nature. Through discussion on each aspect, the elements which scientific development requires while Chinese were lacking in are diagnosed. A lot of typical examples, including ancient Greek and Chinese philosophies, modern Western scientists, and “subject-object dichotomy” vs. “man being an integral part of nature” offer convincing data for the study.