本文以语义为标准对现代汉语存在句进行了重新界定,认为存在句表示处所和事物之间的存在关系,将存在句分为两类共六种基本格式。在此基础上,依据句法-语义界面理论对现代汉语存在句的各种句法结构作了统一解释。此外,本文还提出了存在句的派生格式,认为存在句句首的“在”和“有”分别是话题标记和焦点标记。 In this paper, we redefine the existential sentences of modern Chinese with the semantic as the standard. We think that the existential sentences express the existential relations between the premises and things, and divide the existential sentences into six basic forms. On this basis, the syntactic - semantic interface theory is used to explain the various syntactic structures of the existential sentences in modern Chinese. In addition, this paper also proposes a derived form of existential sentences, which holds that there exists a topic tag and a focus tag at the beginning of the sentence.