The ultimate purpose of this dissertation is to establish a semantic model for the processing of negation in the human brain. In history, the negation has been a primary issue in the study of logic, which regards negation as an instrument applied to the propositions. In the last century, with the development of modern linguistics, negation has become either an effective method to generate non-kernel sentences, as the generative grammar posits, or a measurement for presupposition in pragmatics. The issue of negation also provokes the interest of grammarians who examine it both syntactically and semantically. However most of the above schools investigate the issue of negation at the sentential level. This trend has not been turned until R. Quirk and his colleagues combine the scope and focus with the study of negation. This means the focus of the study has shifted from the sentential level to the inside of the sentences. Following them a number of others put forward solutions to associate the negative marker "not" with the focus of the negation. Their work provides a possibility that, in a negative sentence, what matters is the negative marker and the focus of the negation. This urges the author to assume that the semantic changes that the focus of the negation gives rise to will reveal the mystery of the negation and finally provide a feasible model for the processing of negation.To accomplish the task, the author first divides the lexicon into two types, namely the lexical items of uni-polar descriptions and the ones of bi-polar descriptions. Such a division is necessary because the negation of the former reveals the most general characteristics of the negation, which can be used by the latter. On the other hand, the resemblance that the bi-polar items bear to the oppositeness in semantics supplies the study of negation with abundant literature to draw on, which will reveal more systematic characteristics of the negation.Following such a procedure, the thesis first investigates the negation of lexical items of uni-polar descriptions. To realize the goal, the author refers to a powerful instrument from cognitive linguistics, namely categories and categorization. The author examines different cases of negation with the help of categories and draws a conclusion by the introduction of two parameters: the universe and partial or complete negation. On the basis of them, two principles for negation are set and, most important of all, a semantic model for the negation of uni-polar items is established.Then the author proceeds to investigate the negation of lexical items of bi-polar descriptions. There are three types of such lexical items, which are corresponding to three type of oppositeness, namely complementarity, antonymy and converseness. The negation of these three types is different, thus forming a scale of negation. To the negation of each type, the author assigns a semantic model based on the modification upon the one designed for the negation of uni-polar items.To conclude, there are altogether four semantic models. These four models are closely related to each other and share the identical theoretical background. To unite them under one umbrella term is more suitable than treating them as totally unrelated models. For this purpose and for a visualized effect, the author names his semantic study of the negation the "Book and Pages" theory.