Metoprolol succinate was measured by UV - spectrometry. Results: The pellets containing metoprolol succinate were coated by the mixture of eudragit RS and RL 100 (95: 5) or ethyl cellulose with ratio of coating layer about 16.5% was the best fitted to zero-order kinetics and complied with the specification of USP XXX Conclusions: The present results provided evidence that metoprolol succinate sustained-release pellets can be prepared and be used for effective treatment of hypertension.