Objective：To investigate the correlation between the microsatellite polymorphisms in ob gene 3′flanking region with obesity in Chinese Han ethnicity in Shanghai.Methods: The genotypes of polymorphisms in ob gene 3′flanking region were determined by PCR in 232 Chinese Han subjects (including 130 obese patients and 102 normal controls).The clinical data,including height,weight,waist circumference,hip circumference,body mass index,waist-to hip ratio (WHR),blood glucose,serum insulin,blood lipids,and uric acid,were compared between the 2 groups.Results: No significant difference of genotype frequency (Ⅰ/Ⅰ 0.115,Ⅰ/Ⅱ 0.331,Ⅱ/Ⅱ 0.554 vs Ⅰ/Ⅰ 0.059,Ⅰ/Ⅱ 0.333,Ⅱ/Ⅱ 0.608) and allele frequency (Ⅰ 0.281,Ⅱ 0.719 vs Ⅰ 0.225,Ⅱ 0.775) of ob gene 3′flanking region was observed between the 2 groups.In obese group,patients with Ⅰ+Ⅱ genotype was associated with increased WHR compared with those with Ⅱ/Ⅱ genotype (0.91±0.05 vs 0.86±0.03,P=0.047).Logistic regression analysis showed that WHR was independently correlated with ob gene polymorphisms (P=0.042).Conclusion: Polymorphisms in ob gene 3′ flanking region are correlated with central obesity in obese patients of Chinese Han ethnicity in Shanghai.