To observe the correlation between TCM syndrome differentiation of IgA nephropathy and renal pathology, and explore the basis of TCM microcosmic syndrome differentiation. Methods:A total of 373 patients with primary IgA nephropathy in our hospital from January 2012 to February 2013 were enrolled in the study. The general data of patients, the four diagnoses and syndrome differentiation of TCM, and the pathological data of nephropathy were collected to analyze the correlation between the syndrome differentiation of IgA nephropathy and renal pathology. Results:The common TCM syndromes of 373 IgA nephropathy patients were kidney deficiency syndrome, kidney deficiency with stasis bi syndrome, stasis bi syndrome, wind-dampness syndrome, wind-dampness and stasis bi syndrome, and the liver wind syndrome and wind-dampness syndrome. Immunofluorescence suggested that there was certain correlation between wind-dampness syndrome, wind-dampness and liver wind syndrome and C1q deposition. Katafuchi score could be used as the microcosmic parameter of IgA nephropathy TCM syndrome differentiation, and the score level could reflect the evolution and development of pathogenesis. IgA nephropathy with wind-dampness syndrome had a high score of Oxford classification, which suggested that the renal pathological activity was high and the disease was easy to progress rapidly. Conclusion:The TCM syndrome differentiation of IgA nephropathy is correlated with most renal pathological indexes such as immunofluorescence C1q deposition, Katafuchi score and Oxford classification.