Abstract: GPC/SEC and laser light scattering (LLS) combined technology play a more and more important role in the separation determination of molecular weight and its distribution of macromolecular substances. This method requires less samples, and also was fast and accurate, moreover it could also determine average molecular weight (Mw) , the number average molecular weight (Mn) , Z-average molecular weight (Mz) , Mw /Mn, the second virial coefficient (A2) and root mean square radius (Rg) of the material. GPC/SEC and laser light scattering detection application in protein was summarized. At present, the technology mainly used for the determination of protein molecular weight and its distribution as well as the study of protein aggregation state, and showed its distinctive performance, however, its application in food protein deserved further study.