Objective  To explore the interaction between follicle stimulating hormone (FSH) and transforming growth factor Beta (TGF-β) signaling pathway in rat ovarian granulosa cells.    Methods  The granulosa cells isolated from the follicles of 21 days SD rats. The experiments were divided into three groups: control group, FSH treated group and transforming growth factor beta receptor Ⅱ (TGF-β RⅡ) neutralizated group. Immunocytochemistry (ICC) and Western blotting were then used to locate and detect the expression level of TGF-β RⅡ and proliferating cell nuclear antigen (PCNA). The proliferation index (PI), cell cycle and percentage of apoptotic cells were assessed by flow cytometry (FCM), and the level of estradiol (E2) was determined by ELISA.   Results  FSH increased the expression of PCNA and PI, changed the cell cycle and inhibited apoptosis of GCs, and these actions were reduced significantly when TGF-βsignaling pathway was inhibited(P<0.05); FSH stimulated the secretion of E2, and the increase in E2 levels was not regulated by inhibition of the TGF-β signaling pathway(P>0.05).   Conclusion  The effects of FSH on ovarian granulosa cells are partly affected by the TGF-β signaling pathway.