【正文】 ory concerning human memory. Many years later, it was introduced into reading by Rumelhart, Carrell and Eisterhold. Schema is considered as data structures or world knowledge in the mind and the link between our knowledge of linguistic form and our knowledge of the world is extremely close. The more predictable a sequence of linguistic elements is, the more easily the text will be processed. One definition is Rumelhart’s: “A schema theory is basically a theory about knowledge. It is a theory about how knowledge is represented and about how that representation facilitates the use of the knowledge in particular ways. According to schema theory, all knowledge is packaged into units. These units are the schemata. Embedded in these packets of knowledge is, in addition to the knowledge itself, information about how this knowledge is to be used.”Carrell and Eisterhold further developed schema theory. “The role of background knowledge in language prehension has been formalized as schema theory, which has as one of its fundamental tenets that text, either spoken or written, does not by itself carrying meaning.” That is, according to schemata theory, a text only provides directions for readers to construct meaning from their own previously acquired knowledge. Schema theory is based on the concept that “every act of prehension involves one’s knowledge of world as well” (Carrel and Eisterhold 1983: 73). The understanding of the article depends on the degree of the related schema knowledge being activated. Therefore, teachers should make the most use of the schema theory model in teaching reading prehension in high school and train the students’ ability in order to activate their related background knowledge to assist them in understanding the whole text. Types of schemata Research on the theory of schema has had a great impact on our understanding of reading prehension. Researchers have identified several types of schemata. Generally speaking, there are three types of schemata according to different parts they account for in text prehension. They are language schemata, formal schemata and content schemata, which are closely related to reading prehension. Language schemata Language schemata in reading prehension refer to sentence structure, grammatical inflections, spelling and punctuation, vocabulary, and cohesive structure. Language schemata include the decoding features needed to recognize words and how they fit together in a sentence, that is, the basic knowledge of language. Any reading strategy or skill would be useless for readers who lack basic vocabulary and grammar knowledge. Therefore, the more language schemata the readers have in their minds, the faster and nicer they acquire information, and the better understanding they might achieve. On the other hand, it is impossible for them to decode the language information. As a result, they could not activate the stored knowledge through the clues from the text, let along understand the meaning of the text quickly and exactly. However, in the reading process, we should avoid overemphasizing the isolated words and neglecting the whole text. For example1. Here are some tips for helping to build up one’s schema.2. Some guides have the habit of asking foreign tourists for tips.3. Finally we reached the northern tip of the island. In the first sentence, “tip” means suggestions and advices. In the second sentence, “tip” means a small amount of extra money. In the third sentence, “tip” means the thin pointed end of something. If readers do not understand the meanings of tip or know the isolated meanings of tip and neglecting the whole sentences, they can not prehend these sentences correctly. That is: readers’ lack of enough language schema will hinder their reading prehension. Formal schemataFormal schemata are higher order structures containing knowledge of rhetorical organization structures (Carrell and Eisterhold, 1983: 135). It includes knowledge of different text and genres, and includes the acknowledgement that different types of texts use text organization, language structures, vocabulary, grammar, and level of formality differently. According to the classification of linguistics, reading materials can be divided into such groups as argumentation, exposition, description, and narration. There are various types in daily reading like newspaper articles, reports, poems and so on. Formal schemata guide expectations in our attempts to understand a meaningful piece of language. Take a piece of advertisement as an example. “We do not tear your clothing with machinery. We do it carefully by hand.” This is a piece of tailor advertising. If readers know the features of advertisement, they can prehend it correctly. Advertisements are written concisely and there are many some ungrammatical sentences. The piece of advertisement aims to persuade people into patching clothes in the tailor’s. Therefore, reader store different formal schemata in their mind, they can use the most suitable and effective strategies for different types of texts to improve reading speed. Content schemata Content schemata, systems of factual knowledge, values and cultural conventions, deals with a text’s knowledge content and incorporate background knowledge of the content or subject matter of a text. In other words, content schemata deal with the knowledge related to the content domain of the text, which is the key to understand the texts. Since one language is not only the simple bination of vocabulary, grammar points, and sentence structures, it is also the bearer of different levels of the language’s culture. “one can not learn a foreign language well if he only focuses on the form of language rather than its moral.”(胡文仲，1999：16) For EFL learners, cultural specific knowledge sometimes is crucial in text prehension.For example, readers who have not known American culture may be at a disadvantage when reading “I found my stockings hung by the firepl