Abstract: Objective: To observe the levels of interleukin-18(IL-18) and monocyte chemoattractantprotein-1(MCP-1) in polycystic ovary syndrome(PCOS) patients and to explore that the concentrations of IL-18 and MCP-1 were abnormal in PCOS,and that these cytokines were relevant to insulin resistance or obesity.Methods: Forty-seven PCOS patients(PCOS group) and 29 healthy volunteers(control group) were included in the study.The PCOS patients were divided into two sub groups according to the body mass index(BMI) and homeostasis model assessment(HOMA-IR).According to BMI,30 patients were included in the obese group and 17 in nonobese group;according to Homa-IR,18 patients were included in the insulin resistant group and 29 in non-insulin resistant group.The IL-18 and MCP-1 were compared in each group.The correlation between IL-18,MCP-1 and BMI,waist-hip ratio(WHR),HOMA-IR were also analyzed in the PCOS patients.Results: The levels of IL-18 and MCP-1 in the PCOS IR group and the obese group were significantly higher than those in the non-insulin resistant PCOS group and the non-obese PCOS group(P 0.01).IL-18 levels were positively correlated with BMI and HOMA-IR;MCP-1 levels were positively correlated with BMI,WHR and HOMA-IR(P 0.01).Conclusions: The levels of IL-18 and MCP-1 in PCOS patients increase significantly,which is correlated with IR and obesity.