A simple method, the location staining method, for distinguishing different SOD types was introduced. Due to the different performances of the different types of SOD against inhibitors, .e. g. Cu, Zn-SOD band disappeared in the presence of H₂O₂ or CN^-, MnSOD disappeared in the presence of CHCl₃CH₃CH₂OH, and Fe-SOD lost in the presence of H₂O₂ or CHCl₃-CH₃CH₂OH on the electrophoresis gels, the gels after electrophoresis were treated with the different inhibitors and then stained. According to the loss or presence of these bands, different SOD types can be identified.