Objective：To investigate the role of Chemerin in the pathogenesis of polycystic ovarian syndrome（PCOS）. Methods：Hu－man ovarian granulosa cells（COV434） were cultured in vitro. Down-regulation and overexpression of Chemerin were performed in the COV434 cells. Enzyme-linked immunosorbent assay was used to determine the concentrations of inflammatory factors such as interleukin-6（IL-6），interleukin-8（IL-8），and interleukin-10（IL-10），and tumor necrosis factor-α（TNF-α） in the culture medium. The EdU method and flow cytometry were used to measure cell proliferation ability and apoptosis，respectively. Results：Compared with the negative control group（LV3-NC），the down-regulation groups（LV3-shChemerin-1，LV3-shChemerin-2） had significantly lower concentrations of IL-6，IL-8，and TNF-α and a significantly higher concentration of IL-10 in the culture medium（PIL-6=0.006，PIL-8=0.001，PTNF-α=0.012，PIL-10=0.002），significantly lower proliferative capacity of COV434 cells（P=0.004），and signifi－cantly enhanced apoptosis（P=0.000）. Compared with the negative control group（LV5-NC），the overexpression group（LV5-Chemerin） had significantly higher concentrations of IL-6，IL-8，and TNF-α and a significantly lower concentration of IL-10 in the culture medium（PIL-6=0.044，PIL-8=0.008，PTNF-α=0.015，PIL-10=0.004），significantly higher proliferative capacity of COV434 cells（P=0.013），and significantly reduced apoptosis（P=0.030）. Conclusion：Chemerin plays a role in the development and progression of PCOS by promoting inflammatory response，inducing proliferation，and inhibiting apoptosis of ovarian granulosa cells.