Durability test of commercial polymer electrolyte membranes investigated because longer performance of VRFB depends on the membrane's chemical stability. For hydrolytic stability test, distilled water and membrane was placed in the pressurized container, activated for 24 h at 200 degrees C to check the weight loss, and distilled water's pH change. To confirm the chemical degradation, the membrane was impregnated in 0.1 M V(V) solution for 72 h and concentration change was measured by UV-vis Spectrum. Through this experiment, anion exchange membrane in VRFB is considered in terms of chemical degradation.