Abstract: AIM: To verify sustained-release effects of propranolol hydrochloride sustained-release tablet. METHODS: The comparative bio-availability of propranolol hydrochloride sustained-release and ordinary tablets and the fluctuation of peak-trough concentrations were studied after single and repeated oral administration in 12 healthy male volunteers in a randomized crossover design. An HPLC method with fluorescence detection was used to determine the serum drug concentration. RESULTS: The C_max values of sustained-release and ordinary tablets obtained after single oral administration were 62.4±23.3 and 95.9±12.6 n.*mL^-1, the AUC values were 360.2±80.6 and 383.5±74.2 ng.h.mL^-1, respectively. The relative bioavailability of sustained-release tablet was 95%. The average Cavg values after repeated oral administration were 42.2±12.2 and 32.7±7.1 ng*mL^-1 and the degree of fluctuation (DF) values were 0.90±0.35 and 2.09±0.34, respectively. CONCLUSION: The two formulations were bioequivalent and the sustained-release tablet showed smaller difference between C_max and C_min and smaller DF compared with the ordinary tablet.