Abstract: Based on the semantic dimension of Nida-s classical definition of translation, this paper discusses the role of various semantic categories in translation, which is essentially a process of meaning selection. The proposed selection mechanisms attempt to capture the process moving from static language meaning at the word and syntactic levels to dynamic speech meaning at pragmatic and rhetorical levels in conventional translation. As languages differ in terms of conceptual scopes, syntactic structures, discourse patterns and cultural traditions, it is difficult to achieve full equivalence in translation. Therefore, approximation should be the practical translation criterion to follow.