Objective · To explore the relationship of 11β-hydroxysteroid dehydrogenases (11β-HSDs) in the ovarian granulosa cells and cortisol regeneration in the ovary of polycystic ovary syndrome (PCOS). Methods · In accordance with the revised Rotterdam inclusion/exclusion criteria (2003), 24 patients in the PCOS group were included, meanwhile 21 patients in the control group were included. Follicular fluid and luteinized granulosa cells were collected patients underwent in vitro fertilization(IVF)or intracytoplasmic sperm injection (ICSI) in theCenterforReproductive Medicine of Renji Hospital. Enzyme linked immunosorbent assay (ELISA) was used to detect the cortisol concentration and the cortisone levels of follicular fluid. Real-time quantitative PCR (RT-qPCR) was used to measure 11β-HSDs abundance in the luteinized granulosa cells. The of 11β-HSD1 and 11β-HSD2 in the luteinized granulosa cells were verifiedimmunofluorescence. The correlation of local cortisol level in the ovary with 11β-HSDs in the luteinized granulosa cells was further analyzed. Results · Compared with the control group, the cortisol level in the follicular fluid was elevated in the PCOS group [(477.3±35.3) nmol/L vs (292.0±36.4)nmol/L, P0.014], while no change was observed in the cortisone levels in two groups. Both 11β-HSD1 and 11β-HSD2 were detected in the luteinized granulosa cells. Compared with the control group, the 11β-HSD1 mRNA abundance (P0.033) and reductase activity (P0.006) were increased significantly in the PCOS group, and there was no significant difference in the 11β-HSD2 and oxidase activity between two groups. Consistently, Pearson correlation analysis showed that the 11β-HSD1 but not 11β-HSD2 mRNA levels in the luteinized granulosa cells was correlated with the cortisol level in the follicular fluid (r20.347 6, P0.001). Conclusion · Elevation of local cortisol in the ovary of PCOS patients may be relatedtotheincreased of 11β-HSD1and reductase activity in the ovariangranulosa cells.