Abstract: Objective To analyze the correlation between polymorphism of the angiotensin Ⅱ receptor Ⅰ gene(AT1R,A1166C),environment factors,and the treatment effect of antihyper tensive drug-Bnenapril.Methods To observe the blood pressure of the subjects before and after taking Bnenapril in essential hypertension patients in west of Anhui.Polymerase chain reaction(PCR)combined with restriction fragment length polymorphism(RFLP)were used to detect genetype frequence and polymorphism for AT1R.Results The study revealed that the frequency of allele A and C accounted for 96% and 4% in the total populations.Through chi-square test,it met with H-W balance(χ²=0.31,P>0.05).T he achieved target rates of ?period hypertensives showed the difference between AA and AC/CC groups after taking Benapril.Conclusion This was the first time in China to detect the CC of AT1R(A1166C)gene polymorphism.The Callele of AT1R gene might be receptor sensitivity to the ACEI drugs.