Feng Qi had made a thorough study of logic in ancient China during the late 1970s and early 1980s. He not only argues that there is logic in ancient China, but makes a justification for the pluralism of logic from the perspective of basic contradiction of logical thinking. Influenced by Joseph Needham, he holds that the ancient Chinese showed a constant tendency to develop naive dialectical logic rather than formal logic. By creatively interpreting the ancient discourse on ＂Three Things (三物)＂, he sketches a new system of logical categories which takes lei (类/class), gu (故/reason) and li (理/principle) as its basic skeleton. Besides these concrete studies, he also makes a systematic reflection on the methodological issues about the study of logic in ancient China. Feng Qi＇s such academic achievements will play an important role in the further study of logic in ancient China.