This paper is to summarize understandings on syndrome differentiation in terms of zang-fu pathological changes theory from physicians in different periods,so as to improve the theory and provide new prospects for clinical practice.Methods:By literature analysis and difference comparison,this paper is to summarize and explore historical source,inheritance and innovation of Zang-fu organ syndrome differentiation theory horizontally and vertically.Results:Dating from Huangdi′s Canon of Medicine,the theory of Zang-fu organ syndrome differentiation developed in Treasured Classic,Invaluable Formulas for Emergencies,and Key to the Therapeutics of Children′s Diseases,especially Zhang Yuansu summed up the theory systematically and comprehensively based on his acquisition from Medicine Origin,forming differentiation and treatment theory according to zang-fu pathological changes in principles,strategies,formulas and medicinals.Conclusion:The theoretical system of Zang-fu organ syndrome differentiation makes great influence to the formation of syndrome differentiation theory according to zang-fu pathological changes in later Yishui shcool,warm-recuperation school,strengthening-yang school and other physicians and schools.