Objective：To investigate the expressions of serum miR-21 and miR-93 in patients with polycystic ovary syndrome（PCOS） and their clinical significance. Methods：186 PCOS patients（PCOS group） and 60 healthy women （control group） were se－lected from Central Hospital of Western Hainan. PCOS patients were divided into insulin resistance group（n=121，HOMA-IR≥2.57） and non - insulin resistance group（n=65，HOMA-IR<2.57） according to insulin resistance index（HOMA-IR）. PCOS patients were divided into obese group（n=58，BMI≥28 kg/m2） and non-obese group（n=128，BMI＜28 kg/m2） according to body mass index（BMI）. Real time quantitative PCR （qRT-PCR） was used to detect the changes of serum miR-21 and miR-93 levels in each group. Receiv－er operating characteristic（ROC） curve was used to analyze the diagnostic value of serum miR-21 and miR-93 for PCOS. The correla－tions of serum miR-21 and miR-93 with HOMA-IR were determined using Pearson correlation. Results：The levels of serum miR-21（1.71±0.36 vs. 0.48±0.06） and miR-93（1.93±0.58 vs. 0.75±0.12） in PCOS group were significantly higher than those in control group（P<0.01）. The levels of serum miR-21（2.54±0.83 vs. 0.68±0.10） and miR-93（2.85±1.04 vs. 0.96±0.17） in obese group were significantly higher than those in non-obese group（P<0.01）. The levels of serum miR-21（2.61±0.78 vs. 0.53±0.08） and miR-93（2.91±1.13 vs. 0.82±0.15） in insulin resistance group were significantly higher than those in non-insulin resistance group（P<0.01）. ROC curves showed that the best cut-off values of serum miR-21 and miR-93 for PCOS diagnosis were 1.25 and 1.54，respectively. The AUC（95%CI） of the combined di－agnosis of PCOS was 0.815（0.759 to 0.874），which was significantly higher than that of diagnosis using only miR-21[0.734（0.676 to 0.795）] or miR-93[0.683（0.627 to 0.741）]. Its sensitivity was 83.6%，and its specificity was 76.0%. Pearson correlation showed that miR-21 and miR-93 were positively correlated with HOMA-IR（r=0.842，r=0.775，P<0.01）. Conclusion：Serum levels of miR-21 and miR-93 are high in PCOS patients，and they are associated with insulin resistance. The combined detection of miR-21 and miR-93 is valuable for the diagnosis of PCOS.