Objective To observe the EM>in vitro/EM> effects of angiotensin Ⅱ on cell proliferation of the renal corpuscle in embryonic day 12 mouse kidneys. Methods Pregant female mice(embryonic day 12)were randomly divided into six groups:control group and groups which were induced by different angiotensin Ⅱ(10SUP>-9/SUP>mol/L 10SUP>-5/SUP>mol/L) concentrations. The kidney tissues were cultured for two,four or six days.The proliferating cell nuclear antigen (PCNA) expression was detected by immunohistochemistry and immunofluorescence techniques. Results AngiotensinⅡ promoted cell proliferation of the renal corpuscle. To some extent, the proliferative activity tended to enhance with increasing of the angiotensinⅡ concentration, and the effect had a positive relation to induced time. The proliferative activity at the 4th day was stronger than that at the 2nd day.Conclusion AngiotensinⅡ can promote cell proliferation in the