Abstract:Diversity of seed proteins and isozymes has been widely used for identification of crop cuhivars and evaluation of seed qualities, such as the bread-making potential of wheat, malting and brewing capacity of barley. After elucidation of the rationale for the use of biochemical methods, more attention was paid to various electrophoretic and electrofocusing methods used in identification of different crops which were arranged in the following sequence: selfed or inbred species, out-or cross- pollinating species, Fi hybrids and asexually propagated clones. Recent progress on the application of some new techniques including monoclonal antibody, high performance liquid chromatography and restriction fragment length polymorphism was briefly described.