Rigid poly(gamma-benzyl L-glutamate)/flexible poly(vinyl chloride) (PBLG/PVC) blend membranes were prepared by casting the polymer blend solution in dichloroethane. Structure and morphologies of the PBLG/PVC blend membranes were investigated by Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Thermal, mechanical, and chemical properties of PBLG/PVC blend membranes were studied by differential scanning calorimetry (DSC), tensile tests, and other physical methods. It was found that the introduction of PVC could exert marked effects on the morphology and the properties of PBLG membrane.