“此在”是海德格尔思想的根本范畴,这一概念是他在对形而上学迷雾的认识上提出来的,他指出了传统形而上学的根本错误在于混淆存在和存在者,提出了自己的观念。本文通过对“此在”的内容及性质进行阐述,以此来理解海德格尔对“此在”的诠释。 “This is ” is the fundamental category of Heidegger’s thought. This concept is put forward in his understanding of the fog of metaphysics. He pointed out that the fundamental error of traditional metaphysics lies in the confusion of existence and existence, and put forward his own Concept. In this paper, we will understand Heidegger’s interpretation of “this ” in this article by expounding the content and nature of “in this ”.