Objective:To explore the apoptosis regularity during the development of the mouse kidney. Methods:Both terminal end-labeling technique and stereological methods were used to detect the cell apoptosis in the Kunming mice kidney tissues during the renal development and different process. Results:During the renal development, the TUNEL positive cells were found in the renal cortex and medulla. The peak intensity of apoptosis index (AI) was at postnatal day 14 (P14) in renal corpuscle, while there was no peak value in the renal tubule system. The apoptosis also occurred in the interstitial cells during kidney development. Conclusion:Apoptosis is a basis feature of kidney development and this process can last postnatal 2 weeks. The number of nephron does not increase after day P7, while the structural maturation and differentiation of renal corpuscle still process, which may promote the maturation of real corpuscle filtration.