This paper firstly reviews existing studies on English and Chinese existential clauses at home and abroad. Secondly, it points out problems of contrastive studies between English and Chinese existential clauses at the macro and micro levels. Thirdly, based on the framework of Systemic Functional Linguistics, the paper finds that at the meaning level, existential clauses in English and Chinese both express existential processes, and thus construct existential situations, which involve three basic semantic components: Location, Process and Existent. However, the configurations of these components in the two languages are different. In English, the typical configuration is: There + Process + Existent + Location, while in Chinese, the typical one is: Location + Process + Existent. This remarkable difference lies in that the English and Chinese people experience existential situations in different ways: the English people tend to recognize the Existent firstly and then the Location, whereas the Chinese people recognize the Location firstly. As a result, the different ways of cognition lead to distinct realizations of existential situations in the two languages.