Abstract: OBJECTIVE The pharmacokinetics of hydrochlorothiazide and olmesartan was investigated in healthy volunteers after single administration of compound olmesartan medoxomil tablets. METHODS 30 healthy volunteers were randomly divided into 3 groups and were administered with 1, 2, 3 compound olmesartan medoxomil tablets. Venous blood was obtained timely and the concentrations of hydrochlorothiazide and olmesartan were determined by HPLC. The pharmacokinetic parameters were calculated with software DAS. RESULTS The pharmacokinetic parameters of hydrochlorothiazide of low, medium and high doses were as follows: t1/2 were (9.68±3.37)h, (10.11±4.96)h and (11.02±4.77)h, Cmax were (69.7±19.8)μg·L-1, (158.5±62.4)μg·L-1 and (209.4±85.7)μg·L-1, AUC0→τ were (737.8±110.6)μg·L-1·h, (1397.2±252.0)μg·L-1·h and (2200.3±517.6) μg·L-1·h, respectively. The pharmacokinetic parameters of olmesartan of low, medium and high doses study were as follows: t1/2 were (6.25±1.98)h, (7.99±2.43)h and (7.03±2.86)h，Cmax were (635.1±237.7)μg·L-1, (1336.8±452.0)μg·L-1 and (1774.7±792.2) μg·L-1, AUC0→τ were (4438.4±1058.1)μg·L-1·h, (8239.6±1909.7)μg·L-1·h and (13150.3±3627.5)μg·L-1·h, respectively. CONCLUSION The results suggested that the relationship of dose and AUC for compound olmesartan medoxomil tablets was linear within the dose range and there was no interaction of hydrochlorothiazide and olmesartan in healthy subjects.