【Abstract】Grice had comprehensive studied on implicature from philosophy view. And proposed the cooperative principle and the way of quality， quantity， relevance， four major principles， it laid a good foundation for the study of the implied. This paper reviews the theory of Grice conversation implicature background， combed the related theory， analyzed the existing problems， and for the study of linguistics implied， puts forward a new method of possible research Angle.
【Key words】implicature； cooperative principle； Grice
1. background
From the thirties of the 20th century， western philosophy gradually focused on the methodology. The philosopher stressed the certainty of knowledge and verifiability. They excluded metaphysics and try to establish philosophy on the basis of science. After that， language philosophy came into being. Language philosophy mainly concerns alleged， meaning， truth value， speech ACTS and so on. Their findings laid a foundation for the development of modern linguistics， especially the development of semantics and pragmatics. Many of their view is as a linguistic theories， such as Wittgenstein's theory of meaning and referential， Austin's speech act theory and Grice's cooperative principle， etc. Meaning is derived in terms of its essence， is a kind of reasoning phenomenon in verbal communication. This phenomenon has noticed by many philosophers. On the basis of criticizing and inheriting predecessors' research， Grice's cooperative principle and its maxims are put forward.
2. relation theory
Implicit phenomenon had been a long time. However， Grice done the most most comprehensive and in-depth research. For implicature， Grice proposed many relation concepts. The main concept is： implicature and implicatum； “Natural” and “unnatural meaning”. Grice created implicature and implicatum and they are the core concept on implication research. Grice stated：“I wish to introduce， as terms of art ， the verb implicate and the related nouns implicature （cf .implying）and implicatum （cf .what is implied ）.”（Grice1989 ：24） Grice also distinguish say and implicate. Say is relevance to conventional knowledge（vocabulary and grammar） and opposed to implicate. Grice say：“In the sense in which I am using the word say， I intend what someone has said to be closely related to the conventional meaning of the words （sentence）hehas uttered.”（Grice 1989：25）
“conventional meaning”is not a linguistic term. No matter words or sentences with complex semantic structure， what kind of meaning is the conventional has not yet been determined. There is no clear definition， the implication and meaning of Grice concept has to continue study. It is obvious that Grice has taken the meaning of words in relation to the speaker's intention， to highlight the meaning of subjectivity. “Natural”and“unnatural meaning”distinction is also one of the keys to understand the theory of Grice conversation implicature. All in all， Grice stated conversation as intentional verbal behavior， and proposed implicature and implicatum， distinguish between natural and unnatural meaning， say and implicate. They are the starting point of implicature research.