Objective To investigate the amlodipine or hydrochlorothiazide and valsartan combination thera-py in elderly hypertensive patients with blood pressure variability ( BPV ) and nitric oxide ( NO ) , endothelin role. Methods 552 elderly patients with hypertension were divided into the observation group and control group,276 cases in each group,the observation group was given amlodipine valsartan for treatment,while the control group was received hydrochlorothiazide combined with valsartan for treatment,the two group were treated for three months,the content of BPV,NO and plasma endothelin were analyzed.Results After treatment,the 24hSBPV,day SBPV,24hDBPV,day DBPV of the observation group significantly decreased compared with pre-treatment, the difference was statistically significant(t=20.09,15.97,9.31,9.41,all P<0.05),patients in the control group only 24hSBPV and day SBPV [(9.12 ±2.57)%,(8.43 ±1.97)%]were significantly lower than before treatment(t=12.31,9.53,all P<0.05);The day SBPV,24hDBPV,day DBPV[(7.21 ±1.34)%,(12.31 ±2.54)%,(10.59 ±2.73)%]of the ob-servation group after treatment were significantly lower than those of the control group(t=10.52,12.34,8.35,all P<0.05);The NO[ (66.12 ±23.57)%,(68.29 ±21.52)%]and endothelin levels[(34.43 ±7.97)%,(34.21 ± 7.34)%]of the two groups after treatment were significantly lower than those of before treatment(tobservation grou P=31.39,11.79,tcontrol grouP=28.31,9.35,all P<0.05).Conclusion The amlodipine or valsartan hydrochlo-rothiazide used clinically can effectively control blood pressure, significantly increase NO levels, decrease plasma endothelin levels,which is worth to be used in the clinical.