在当今社会，英语作为一种最重要的信息载体，已成为人类生活各个领域使用最广泛的语言。而英语写作，作为一种交流手段，在信息沟通与传递过程中,起着重要的作用。此外，写作作为一项基本技能，在北京英语高考试卷中占有很大的分值，约为全卷的25%(35/150)。它体现语言学习者综合运用语言的能力。然而，在现实教学过程中，老师及学生都很受挫。老师过于依赖传统教学理念，侧重语法的系统化讲解而学生缺乏学习策略培训。所有这些表明，英语写作在英语学习过程中应赋予更多的重视。 研究者发现，词块策略能提升高级学习者的写作能力。为了探究词块策略能否提升以及如何提升高中生的写作能力，作者在自己所任教的两个高二班级进行了为期16周的实验。其中一个班作为实验班，另一个班作为控制班。并且，所有参加实验的学生都处于中低水平(与通州区的英语统考平均分相比，作者所在学校的所有学生都处于中低水平)。在实验过程中，实验班以词块为切入点进行写作训练，而控制班则以传统常规教学方式进行写作训练。 为了使实验更有信度和效度，作者分别在实验前后进行了一次调查问卷，一次写作检测和实验后的一次访谈。写作检测与调查问卷收集的数据通过SPSS17.0统计软件进行分析。访谈收集的信息，作者本人进行质性分析处理。实验结果表明:(1)词块策略极大的提高了学生的写作能力。在一定程度上,改善了写作语言的准确性与句式多样性。与此同时，词块策略也提升了学生习作中的词块意识并改善了他们对英语写作的态度。(2)词块策略对不同层次的学生产生不同程度的影响。与低水平的学生相比，中间层次的学生使用的词块数量更多，取得的进步更大。

In modern society, as the information carrier, English has been widely used in our social life. English writing, as a means of communication, plays a significant role in the communication and transmission of information. In addition, as one of the four basic skills (listening, speaking, reading, writing), writing occupies a large part, accounting for nearly 25%, 35 scores out of 150 scores. Besides, writing represents the learners＇overall language competence.However,in reality,teachers and students are all frustrated by writing. Most teachers still heavily depend on explanation of English grammar systematically while students are lack of learning strategy training. All of these show that English learning should attribute more importance to English writing. Researchers have found that lexical chunks strategy can greatly promote advanced learners' writing proficiency. Therefore, the author aims to explore whether and how lexical chunks strategy has an effect on students' writing in senior high school. Specifically, the author conducts a 16-week experiment in two classes in Grade two, one as a controlled class, the other as an experimental class. All of these students are taught by the author herself and they are all of intermediate or low level, compared with the average score of Tongzhou District. During the whole experimental period, students in experimental class are taught to write with lexical chunks strategy while students in controlled class are taught in a traditional way. To make the research more reliable and valid, the author carries out one writing test and one questionnaire before and after the research respectively and an interview after the research as well. All of the data from the writing tests and the questionnaire are collected and further analyzed by SPSS 17.0. The data from the interview are analyzed qualitatively. The result reveals the following points. On the one hand, lexical chunks strategy greatly enhances students' writing proficiency. To some degree, it improves language accuracy and the diverse of sentences. Besides, lexical chunks strategy greatly promotes their awareness of lexical chunks in writing and changes their attitude toward writing as well. On the other hand, lexical chunks strategy has a different effect on students of different levels. The students of intermediate level make greater progress than those of low level. So does the number of lexical chunks in writing.