Abstract: Given the limitations of cognitive pragmatics, this paper proposes Diachronic Cognitive Pragmatics integrating diachrony, cognition and pragmatics. It is intended to expound the entrenchment-conventionalization process of pragmatic meanings from a diachronic perspective, revealing the paths of changes in word meanings. The paper argues that utterance-token meanings evolve into utterance-type meanings through entrenchment, and utterance-type meanings evolve into new coded meanings through conventionalization. Different types of meanings are not easy to be distinguished, as a result of the frequency of repeated usage. This study sheds new light on the study of polysemy of words.