The derivation of the conversational implication for expressing politeness in Japanese are governed by a set of pragmatic rules. The purpose of this study is to find out the relation between the system of polite expressions in Japanese, the speech style and the interpersonal impression from a pragmatic and psychological perspective. And results show that the psycological distance between speakers and adressees and the speech style of polite expressions are not correlated, and speakers' speech style and the expectation of hearers' toleration for using non-polite expressions are mutually related.