Controlled drug release technology is becoming a commercially sound methodology of administering pharmaceutical therapies,and it is important to predict and control the release kinetics to fully take advantage of this technology.Carboxylmethylchitosan (CMCS) and alginate (SA) blend membranes were successfully prepared by solution casting technique and exposing to acetic acid atmosphere,which induced the protonation of the amino groups of CMCS,and the formation of polyelectrolyte composite hydrogels.By using diclofenac diethylamine as the model drug,the diffusion controlled drug release behaviors of the membranes were studied based on permeation experiment,which indicated that the swelling rates of the membranes could be adjusted by simply changing the weight ratio of CMCS/SA and effectively changed the release rate of the membrane.The study shows that CMCS/SA blend membranes are promising biomaterials used for modulating the permeation behavior and developing advanced drug delivery systems.