Abstract: Objective Renin-angiotensin-aldosterone system（RAAS） plays important role in the development of hypertension. Aldosterone is an important component in RAAS. The present paper is intended to investigate the relationship of aldosterone synthase（CYP11B2） gene -344C/T polymorphism and essential hypertension in Chinese people. Methods One hundred and seven patients with essential hypertension were enrolled into this study. 127 heathy people were as control group. DNA was extracted from white blood cell. Segments of CYP11B2 were amplified from DNA by polymerase chain reaction（PCR）. PCR products were restricted with 5 U of Hae Ⅲ for 2 hours at 37 ℃. The digested products were subjected to electrophoresis in 2.5% agarose gels and stained with ethidium bromide. Results 1.Clinical characteristics and biochemical examinations showed, blood pressure, total cholesterol in essential hypertension was significantly higher than those in the control. 2.The frequency of CYP11B 2 -344C/T genotype in the hypertensive cohort and controls were CC:0.06 vs 0.04; CT: 0.28 vs 0.48; TT:0.66 vs 0.48 respectively. Allele frequencies were C:0.20 vs 0.28; T:0.80 vs 0.72. In this study, The frequency of the TT genotype, T allele in hypertension was significantly higher than that in the control. CT genotype, C allele was significantly lower than that in the control group（ P ≤0.05）. Conclusion The -344C/T polymorphism in the CYP11B2 gene is associated with essential hypertension in China. T allele may be a genetic marker in essential hypertension in China.