As one of the three major elements of language, vocabulary plays a vital role in communication. The dramatic increase in vocabulary is a distinctive characteristic of English subject to the new curriculum reform. Thus, many scholars at home and abroad have focused their research on how to optimize the approaches to teaching English vocabulary to improve the capacity of vocabulary application in communication. In fact, the context is closely related to the meanings of words. Context is the key to vocabulary teaching. In order to carry out English vocabulary instruction effectively and raise students’ capability of vocabulary application, namely, using them correctly in the context, the author of this paper conducted an empirical experiment based on the theory of context using new curriculum teaching materials.In this study, as subjects, two parallel classes were selected from one high school, a total of94students, and with the help of questionnaire survey, classroom training and test, a semester-long experiment was carried out. Firstly, a questionnaire was conducted to get an idea of the strategies students used in learning and memorizing vocabulary, based on which the author makes a comparative study in two classes. The author of this paper used the context teaching method in the experimental class, especially in the stages of presentation and consolidation while she used the traditional teaching method in the control class. To test the students’ vocabulary size, the thesis uses the Dictionary Method. Pre-test and post-test were adopted to compare and measure the two groups. Statistics analyzed by the SPSS17.0software indicate that the experimental group did prominently better than the control group at the end of the semester, therefore, the result of the experiment proves that:1. Context-based approach of vocabulary teaching can activate students’ interest in vocabulary learning and improve students’learning strategy on vocabulary.2. Context can help students consolidate vocabulary in a much better way, and enlighten the students to improve their competence of vocabulary application, thus achieving long-term memory.After the experiment, a discussion is held on valuable experience and problems, corresponding suggestions are given, for example, the context should be designed to stimulate the students’interest; the teacher should lead the students to acquire the vocabulary learning strategies, and so on. The author hopes to offer help to improve high school English vocabulary teaching and learning and enlightenment to teachers in better use of context theory in high school English teaching, which is also the requirement of the new curriculum.