Aim To ascertain whether N-acetylcysteine(NAC) is helpful for hypertension or not.Methods Male spontaneously hypertension rat(SHR) were randomly divided into three groups:placebo group,NAC group,and base group.Rats in the base group were sacrificed before treatment,and blood samples were detected.Syntolic blood pressure(SBP),nitric oxide(NO),and interleukin-1(IL-1) was measured in placebo group and NAC group.Results The SBP of placebo group was higher than NAC group after treatment.NO was higher in NAC group than placebo group(p<0.05).IL-1 was higher in placebo group than NAC group(p<0.05).Conclusion NAC(10 g/L) can step down blood pressure in spontaneously hypertension rat,and has protective effects on it.