To study the toxic effects and explore the possible mechanism of chlorpromazine exposure to rat ovarian granulosa cell steroidogenesis in vitro，immature ovarian granulosa cells of wistar rat was primary cultured. After exposure to chlorpromazine for 24 h, cell viability was detected by MTT assay, content of progesterone (P) and estradiol (E2) collected from medium were detected by ELISA assay; FSHR, StAR, P450scc and P450arom mRNA expression were detected by semi-quantitative RTPCR, and expression of follicle stimulating hormone receptor-specific receptor(FSHR) in granulosa cells was detected by immunocytochemical staining assay. The results showed that chlorpromazine could significantly decrease the viability of rat ovarian granulosa cells, thus affect steroidogenesis and StAR maybe one of the key factors to affect the steroidogenesis of granulosa cells.