Objective To study the relationship of single nucleotide polymorphism of angiotensin converting enzyme 2 ( ACE2 ) with essential hypertension(EH) and antihypertensive response of valsartan.Methods A total of 120 case EH patients was received valsartan once daily for four weeks.Direct DNA sequencing was performed to detect the signgle nucleotide polymorphisms of ACE2 in 120 EH patients and 60 controls with normal blood pressure.ResultsThe genotyping data indicated that there were significant differences of G allele frequency between male or female EH group and controls( x2 =5.310,4.423,P ＜0.05 ).Treated with valsartan,patients with.G allele were not found to be associated with reduction in blood pressure( P ＞0.05).Conclusions Our data suggest that the ACE2 G8790A signgle nucleotide polymorphisms might be involved in the development of EH.The risk developing hypertension in the people carrying G allele is higher than that in those carrying other allele.Therefore,ACE2 gene might be a sensitive gene associated with EH.