Abstract:Deacon's theory of language evolution can be summarized as follows.(1) Language is a complex adaptive system.Language acquisition is not a simple question of nature or nurture, but highly depends on our learning bias for language.The core similarities of language structures emerge from synergic effects of various constraints, and there is not an innate genome to be the basis of human capacities of language acquisition and universal grammar (UG).(2) There is not any evolutionary plausibility for the "UG" termed by Noam Chomsky.Natural selection can explain the evolutionary process of language.Baldwin effect, genetic assimilation and "lazy gene" effect can play active roles in the explanation of the co-evolution of language and brain.(3) The emergence of the systemic use of symbols whose selective advantage is probably to loosen the pressures brought by social life and to make communication more conve-nient for hominid, is one of the most important steps in the evolution of language capacity, which is helpful to the building of the ecological niche construction useful to human survivals.Though this theory can be more consistent with the experimental fruits from the up-to-date development of evolutionary biology, especially evolutionary neuroscience, it has to answer many profound questions related to language acquisition and the core similarities of language structures.