For region, there is only difference for the association between eNOS rs1799983 polymorphism and hypertension under overdominant model, when GT was compared with GG + TT, the association with risk of hypertension was identified in China (OR 1.29; 95% CI 1.12–1.49), and the association between eNOS rs1799983 polymorphism with risk of hypertension was found in any region under other genetic models. The gene discussed is NOS3; the disease is Hypertension.