As a key issue in theoretical linguistics,argument structure attracts a great deal of attention from Cognitive Grammar and Construction Grammar.Cognitive Grammar,which emphasizes the encyclopedic nature of meaning,construes the semantic base by means of independently motivated cognitive methods.It can provide important insights for the study of constructional motivations as well as the fusion between the verb and the construction in Construction Grammar.Construction Grammar,on the other hand,stresses the top-down approach in the study of argument structure,and calls for Cognitive Grammar to attach more significance to the representation of constructional meaning.These two theoretical frameworks,despite their different focuses,can be unified and become mutually complementary.In this way,they can achieve more explanatory power for argument structure.