Objective To investigate the association of the Cx37 polymorphism of connexin gene with essential hyper?tension (EHT) in Xinjiang Han and Kazak population. Methods In Xinjiang region, 500 EHT patients (EHT group) were in?cluded in this study including Kazak 250 cases and Han 250 cases. Five hundred healthy volunteers (NT) were used as NT group including Kazak 250 cases and Han 250 cases. The values of age, body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure (DBP), and other general clinical features were compared between two groups. The poly?morphism of Cx37 gene rs1630310, rs697372 and rs705193 SNP were compared between EHT and NT groups in the two eth?nic groups. Hardy-Weinberg equilibrium was used to detect the representation, and differences of genotype frequencies and gene frequency were calculated in two groups of Kazak and Han groups. Results There were significant differences in BMI, SBP, DBP, apolipoprotein ratios and homocysteine between EHT group and NT group in Kazak and Han groups (P<0.05). There were no significant differences in genotype frequencies and gene frequencies of rs705193 between EHT and NT groups (P>0.05). The differences of Kazak rs1630310 genotype and gene frequency were statistically significant (P<0.01). The frequency of Kazak rs697372 locus genotype was not significantly different (P>0.05), but the difference of gene frequen?cy was statistically significant (P<0.05). There were no significant differences in rs1630310 and rs697372 locus genotype and gene frequency in two groups of Han group. Conclusion Cx37 gene polymorphism is associated with the occurrence of EHT in Xinjiang Kazak population, which may be related with the rs1630310 and rs697372 polymorphism.