Objective:To study the parametric feature of ambulatory blood pressure in elderly patients with hypertension of yin deficiency and yang excess syndrome. Methods114 cases of elderly patients with hypertension were selected,among 50 cases were of yin deficiency and yang excess syndrome,64 cases were without the syndrome of yin deficiency and yang excess. 24 hours ambulatory blood pressure monitoring was performed in all patients. The differences of ambulatory blood pressure parameters were compared between the two groups.  Results:①The systolic blood pressure(SBP)and cerebral infarction rate in the group with syndrome of yin deficiency and yang excess were higher than those in the group without this syndrome(P<0.05). There were no statistically significant differences on the blood lipid,blood glucose and liver and renal function between the two group(P>0.05). ②Comparison between the two group,the values of 24 h average systolic blood pressure (24 hASBP),daytime average systolic blood pressure (dASBP),24 h mean pulse pressure (24 hMPP),daytime mean pulse pressure (dMPP),daytime mean arterial pressure (dMAP),24 h systolic blood pressure variability (24 hSBPV),24 h diastolic blood pressure variability (24 hDBPV),daytime systolic blood pressure variability (dSBPV),24 h systolic blood pressure load(24 hSBPL),24 h diastolic blood pressure load(24 hDBPL),daytime systolic blood pressure load(dSBPL) and morning blood pressure peak (MBPP) in the group with syndrome of yin deficiency and yang excess were higher than those in the group without this syndrome(P<0.05). ③Comparison of circadian rhythm of blood pressure between the two groups,the constituent ratio of dipper in the group with syndrome of yin deficiency and yang excess was higher than that in the group without this syndrome(P<0.05),the constituent ratio of reverse-dipper in the group with syndrome of yin deficiency and yang excess was lower than that in the group without this syndrome(P<0.05). ④Spearman correlation analysis results showed that there were correlation between the existence of yin deficiency and yang excess syndrome and the descend rate of SBP,complicated cerebral infarction,24 hASBP,dASBP,24 hMPP,dMPP,dMAP,24 hSBPV,24 hDBPV,dSBPV,24 hSBPL,24 hDBPL,dSBPL,MBPP,night systolic blood pressure(nSBP)(P<0.05).⑤Binary logistic regression analysis results showed that dASBP was the independent factor for elderly hypertension of yin deficiency and yang excess syndrome.  Conclusion:①The parameters changes of ambulatory blood pressure in elderly patients with hypertension of yin deficiency and yang excess syndrome were mainly presented as the increase of systolic blood pressure parameters,and the diastolic blood pressure parameters were not obviously changed,which accompanied by the large blood pressure variability,the increased blood pressure load,the prominent morning peak and the circadian rhythm disorders. ②In all the differential factors,dASBP was most closely related to elderly hypertension of yin deficiency and yang excess syndrome,which may be used as the characteristic index. Clinical application should pay attention to the ambulatory blood pressure monitoring for patients with yin deficiency and yang excess syndrome,and implement the treatment according to syndrome differentiation as well as individualized treatment,so as to reduce the complications and damage of target organs,improve the clinical efficacy and life quality of patients.