Abstract: Objective:To explore the expression of BID and the relation between cell proliferation and apoptosis at various stages of IgAN. Method:The expression of BID、PCNA and FN in renal tissue were detected by immunohistochemistry, TUNEL and light microscope were used to detect apoptotic cells. Result:With the progress of IgAN, the expression of BID、PCNA、the number of apoptotic cells and FN increased gradually (P< 0.05),especially in IV group(PCNA：Ⅳ is in the same rank as Ⅲgroup), The expression of BID in glomcrulus had positive correlation with the rate of apoptotic cells、the express of PCNA and FN、the rate of glomerular sclerosis and urine protein，and had negative correlation with glomerular filtration rate(P<0.01).Conclusion: BID can accelerate the progression of IgAN through promoting disequilibrium of cell proliferation and apoptosis，and it may serve as a marker for judging prognosis.

Key words: BID Protein, apoptosis, TUNEL, PCNA, FN, IgAN