Abstract: The aim of this study was to prepare raxatidine acetate hydrochloride (ROX) intragastric retention tablets and to study their in vitro releasing features.According to the cumulative release and floating capacity,formulations were optimized by single factor screening and orthogonal design with 3 factors and 3 levels .The optimal formula were ROX 75 mg,HPMC K100M-chitosan (0.15 Pa·s) (2∶1) 140 mg,sodium bicarbonate 50 mg,lactose 35 mg,magnesium stearate 3 mg.The optimized tablets could float within 3 min and maintain for over 8 h,ideal sustained release characteristics in vitro coincided with zero-order kinetic and Higuchi equation.Prepared tablets showed good floating during the whole release process,and sustained release properties.The formulation and preparation technique were simple and feasible.