Objective: To optimize the formula of total alkaloids of Aconitum sinomontanum Nakai sustained-release tablets and evaluate its drug release property.Method:Orthogonal design was used to obtain the best formula.The best formula was determined by dissolution of lappaconitine in total alkaloids of Aconitum sinomontanum Nakai sustained-release tablets and comprehensive scoring method.The release formula was made to investigate the release mechanism.Result:The dissolution curves in-vitro showed that the drug release could be best described by the Higuchi equation（Q = 0.349 t1/2-0.150 5

r = 0.997 2） and Peppas equation（lnQ = 0.688 9 lnt-1.595 7

r = 0.995 5）.It showed that the release mechanism were Fick diffusion and backbone corrosion.The release rate matched the requirement of quality control on sustained-release tablets in Chinese Pharmacopoeia（2005）.Conclusion:The method of content determination was simple and sustained-releasing rate was significant.The release mechanism followed the kinetic model of sustained-release tablets.It is worth doing further research for clinical use.