Eighteen Chinese male subjects com-pleted a single-blind, randomized, three-treatment, theree-period, cross-over study. In each treatment phase, subjects received a single dose of 20mg isosr-bide dinitrate (CAS 87-33-2,ISDN) intra-venous infusion, 20mg isosorbide 5-mononitrate (CAS16051-77-7,5-ISMN) tablet or 20 mg isosorbide 5-nibibutrate intravenous infusion. Each conseeutive dosing was separated by a washout period of 7 days, Following each dosing, venous blood samples were collected over a period of 16h. Pladma concentra-tions of isDN and its two active metabo-lites isosorbide 2-monorlitrate (2-ISMN), 5-ISMN had been measured by a valid-atcd gas chromatographic method. Vari-ous pharmacokinetic parameters includ-ing AUC0-T. AUC0-x, Cmax Tmax T1/20 Ketm and MRT were determined for the three fornulations and fouud to be in good agreement with literatiie values. AUCO-1 and AUC0-x of 5-ISMN tablet and intrave-nous infusion were 2694