Background Combination therapy is an effective method to reduce the blood pressure (BP) for patients with hypertension.This study was performed to evaluate the efficacy and safety of benazepril/lercanidipine compared with benazepril alone in patients with mild-to-moderate hypertension.Methods One hundred and eighty-one patients with mild-to-moderate primary hypertension were assigned in this randomized,single-blind,parallel-group study and were randomly divided into group A (benazepril 10 mg/lercanidipine 10 mg) and group B (benazepril 10 mg) for 8 weeks.At 4 weeks,the dosage of Benazepril was titrated up to 20 mg if the diastolic blood pressure (DBP) remained ≥90 mmHg.BP control and side effects were evaluated at the end of 1,4 and 8 weeks.Results The baseline characteristics of the two groups were similar.The BP in both groups decreased from the baseline (P ＜0.05).At the end of 4 and 8 weeks,Benazepril/Lercanidipine produced greater BP reduction than Benazepril alone (P ＜0.05).The comparison of the rate of BP control for the benazepril/lercanidipine and benazepril groups at the end of 1,4,and 8 weeks were 41.2％ vs.37.6％ (P ＞0.05),67.1％ vs.44.7％ (P ＜0.05),and 71.8％ vs.45.9％ (P ＜0.05).There was no significant difference of side effects between the two groups.Conclusion The benazepril/lercanidipine combination is more effective in reducing BP than benazepril alone,while it does not increase the incidence of side effects.