It has been pointed out by Professors Charles N. Li and Sandra A. Thompson (Mandarin Chinese: a functional reference grammar, p. 33) that not all adjectives in Chinese can undergo reduplication and that there does not appear to be any rule governing which adjectives can be reduplicated and which adjectives cannot. The present paper argues that, contrary to Li and Thompson's analysis, there are very general rules concerning reduplication of adjectives in Chinese. The reduplication of monosyllabic adjectives, for example, is mainly dependent on a semantic consideration as to whether adjectives express an objective assessment or an subjective evaluation. The reduplication of disyllabic adjectives, on the other hand, is constrained not only semantically but also morphologically (e.g. whether the adjective is a subject-predicate construction, a verb-object con-struction, a verb-complement construction, an endocentric construction or a coordinate construction, and whether the constituent morpheme is free or bound) as well as stylistically (e.g. whether the adjective is colloquial or literary in usage). In passing, the syntactic functions of Chinese adjectives in general and a distinction between the adjectival use and the adverbial use of reduplicated adjectives have also been discussed.