OBJECTIVE： To prepare Bevacizumab （BEV） multivesicular liposomes （BEV-MVLs） with sustained-effect， and to study their in vitro release characteristics. METHODS： BEV-MVLs were prepared by double emulsion method. Box-Behnken design-response surface methodology was used to optimize the prescription with the concentration of glycerol trioleate （TO） in organic phase， ratio of 1，2-dioleoyl-sn-glycero-3-phosphocholine （DOPC）-cholesterol （CH） （mol/mol）， the concentration of L-lysine in external water phase as factors， using encapsulation rate as index. The morphology of BEV-MVLs was observed by inverted fluorescence microscope and SEM； particle size was determined by laser particle size analyzer； the BEV content was determined by HPLC and calculate the encapsulation rate and in vitro accumulative release rate. RESULTS： The optimized prescription was as follows as TO of 2.72 mmol/L in organic phase， DOPC-CH ratio of 0.67 （mol/mol） and L-lysine of 40 mmol/L in external water phase. The encapsulation rate of BEV-MVLs was （80.65±4.42）％ （n＝3）， and relative error of it to predicted value was 2.54％. The liposomes were spherical in appearance shape and uniform in size， and they were typical non-concentric vesicle structure with average particle size of 16.80 μm. 30 d in vitro accumulative release rate was about 92％. CONCLUSIONS： Prepared BEV-MVLs show sustained-effect， and their encapsulation rate reaches the expected effect.