Objective To prepere vinpocetine sustained release matrix tablets by sodium alginate as the hydrophilic polymer and investigate of the influencing factors in drug release from matrices.Methods With sodium alginate as the matrix,the tablets were prepared by the direct compression method.The dissolution of vinpocetine from prepared tablet formulations was performed according to the Chinese Pharmacopoeia(2000) Dissolution Apparatus Ⅱ(the paddle method).The investigation of the influencing factors,such as the content and viscosity of sodium alginate,the amount of citric acid,ionic strength and pH value of dissolution media,on the drug release behavior was performed by measuring the drug cumulative released percent.Results and Conclusions The results showed that the content and viscosity of sodium alginate ,the amount of citric acid,ionic strength and pH value of dissolution media all have significant effect on the drug release behavior.Interestingly,the zero-order release of the drug can be produced by regulating the amount of citric acid added to the sodium alginate,which can provide valuable information and be useful for further research on the controlled-release vinpocetine matrices.