Abstract: Objective To investigate the correlation of thyroid hormone levels and the insulin resistance in adolescents with polycystic ovary syndrome (PCOS). Methods Ninety-two girls with PCOS and sixty age-matched controls underwent clinical,biochemical,hormonal evaluation.Waist-to-hip ratio (WHR),blood glucose,insulin and lipid levels were compared between the two groups.The relative indicators in patients with TSH ≥ 2.5 m IU/L and TSH<2.5 m IU/L were also observed.Due to WHR influence factors,the partial correlation analysis was made between TSH,FT3,FT4 and HOMAIR,blood lipid and blood sugar. Results 1PCOS had elevated fasting plasma glucose,insulin,HOMA IR and thyroidstimulating hormone (P<0.05);2PCOS with TSH ≥ 2.5 m IU/L had significant differences in plasma glucose,insulin,HOMA IR and thyroid-stimulating hormone as compared with another group (TSH<2.5 m IU/L),P<0.05;3Controlling the WHR influence factors,TSH was closely associated with FBI and HOMA-IR in the group TSH ≥ 2.5 m IU/L,while FT4 had obviously positive correlation with TG and FBG (P<0.05).Nevertheless,negative correlation was illustrated in the area of FBI and HOMA-IR (P<0.05),however,another group (TSH<2.5 m IU/L) showed less close correlation. Conclusion Adolescent PCOS girls with TSH ≥ 2.5 m IU/L have more obvious insulin resistance and higher WHR.However this effect of TSH on IR may be independent of WHR.