This study investigated the usage patterns and historical changes of Archaic Chinese proximal demonstratives 玆, 此, 是, 斯. By employing edition comparison method, the study examined how these demonstratives were used in different ways in ancient, recovered documents of Lao Tzu, the Discourses of Confucius, and Black Robes in the Book of Rites, respectively, to identify the problem. Additionally, the study pinpoints and describes syntax structure, pragmatic functions, and grammatical functions where the four demonstratives were utilized by thoroughly examining documents from the age of Archaic Chinese, such as Bronze Inscriptions. The findings showed that the differences in demonstratives pragmatic and grammatical functions go through a specific grammaticalization process in association with common syntax structure. For instance, if a derivative with discourse deictic(pragmatic) and substitute function(semantics) that is accompanied by a VP predicate is used as a sentence-initial element, it is grammaticalized into sentence connectives. Surprisingly, the outcomes of grammaticalization match the character replacement usage patterns shown in the editions mentioned earlier.