Abstract: The methods of protein extraction and SDS-PAGE were compared and optimized in woody plants. The improved steps included modified protein extraction, substitution of ethanol for methanol in the solution of staining and destaining. Satisfied results were achieved in the application of the optimized method to the protein analysis of several woody plants. 66 kD protein band related to salt stress and 28 kD protein band associated with osmotic stress were obviously showed out in the analysis for the suspensivly cultured cells stressed with NaCl of Populus euphratica.