本文就日语助词“は”和“が”在句中的语法功能和表意特点进行了考证,论述了助词“は”标示单句主语时,句子的表意重心在谓语部分;标示复句主语时,标示主句主语,与句尾的谓语呼应使用。另外助词“は”还有取代其他助词或接在其他助词后起到提示作用。助词“が”用于表示单句主语时,很多场合语义重点在主语部分。用于复句主语时,主要标示分句主语,其功能与其他格助词一样,表示分句里的句子成分。在需求和愿望意义的句子里,“が”还可以表示需求或渴望的对象。两助词虽然都用于标示主语,但是在语法功能和表意特点上有着明显的不同。 In this paper, the grammatical functions and ideographic features of Japanese auxiliary words “wa ” and “ga ” are investigated. When the auxiliary word “は ” is used to indicate the single sentence subject, the sentence’s center of gravity is in the predicate part. When the compound sentence is subject, the subject of the main sentence is marked and the predicate at the end of the sentence is used. Additional auxiliary word “” “は ” also replace other auxiliary words or after other auxiliary words to play a hint. Particle “ ga” is used to represent a single sentence subject, the semantic focus of many occasions in the subject part. When used in the complex sentence subject, the main subject of the clause is marked, and its function is the same as that of other cell auxiliary words, which means the sentence component in the clause. In the context of needs and desires, “ga ” can also represent the object of desire or desire. Although the two auxiliary words are used to indicate the subject, but there are obvious differences in the grammatical functions and ideographic features.