Objective To observe effects of angiotensin Ⅱ(AngⅡ) on proliferation and apoptosis of developing mouse renal corpuscle, derived from the 12-day embryo EM>in vitro/EM>. Methods Totally 40 pregant female mice(embryonic 12 days)were randomly divided into six groups: control group and groups which were induced by different concentrations of Ang Ⅱ(10SUP>-9/SUP>-10SUP>-5/SUP>mol/L). The kidney tissues were cultured for 2，4，6 days. Immunohistochemistry(PCNA and TUNEL),double immunofluorescence and laser scanning confocal micropcopy were used to observe the expressions of PCNA and TUNEL positive cells in mouse renal corpuscles at different developmental stages. Results AngⅡ was able to induce the renal corpuscular proliferation and apoptosis to a certain degree,and the effects were in accordance with AngⅡ concentration and inducing time. The shorter AngⅡ-induced time or the lower concentration of AngⅡ was the more effective on the proliferation, on the contrary, the longer AngⅡ-induced time or the higher concentration of AngⅡ, the more significant effect on the apoptos