As a teacher leading students to hold the description of negative language is a very important job in the process of teaching.

There are many different view points about the essence of natural language negation:negation means"absence,non-existonce"; negation can express various pragmatic meanings;negation is a constituent of thought and sentence which expresses thought,and so on.

And negation in our natural languages turns out to be so complicated that the traditional unitary account proves ineffective either for negation in general or for the so-called metalinguistic negation in particular.

Instead, I will restrict my discussions to a cognitive study of metalinguistic negation, a special kind of negation.

As an important part of negation and natural linguistic phenomenon, metalinguistic negation has drawn more and more attention of researchers in recent years; however it is noteworthy that much attention has been contributed to describe MN from semantic and cognitive point of view, few endeavors have been made on explaining MN from pragmatic perspective.