Besides, according to The English Curriculum standard (2011), the aim of the English course in stage of compulsory education is to help students develop comprehensive linguistic competence, promote their mental development and improve students’ humanistic quality. That is to say, rather than simply teaching the linguistic knowledge, a successful English class in primary school should also be involved in several other elements: linguistic skills, affects and awareness, learning strategies and culture consciousness. 

Although in nowadays education area, a lot of efforts have been put for successful implementation of different techniques in teaching English as a second language, there are still many problems teachers and students face in the language classroom, like the difficulty in vocabulary memory, for example. We need to make changes in the educational process, otherwise there will be more barriers students and teachers will be unable to overcome in the future. The elements in The English Curriculum standard (2011) set a high requirement for English instructors, asking teachers to change the traditional teacher-centered education approach into a new student-centered one. Even for vocabulary teaching, new methods and approaches should be adopted to promote students effective word memory. So how to help students to remember the English words effectively has been a hot issue. It is time for us to use powerful, creative and adaptable techniques in teaching and learning languages, especially for students’ remembering vocabularies.源]自=优尔-^论-文"网·www.youerw.com/

1.2 Significance of the research

Mind mapping is an active learning strategy, focusing on the combination of abstract thinking with imaginal thinking. This technique originated from the theory of radiant thinking, or the full brain actively thinking of associations driven from a central concept (Buzan & Buzan, 1996). He described the technique as “working harmoniously with the way human’s brain and processing the information.” In the duration of using the mind mapping technique, creating new ideas and problem solving emerges when the mind is allowed to think radiantly or freely. This technique is also a graphic illustration using words, images, colors, and branches that extend from a central idea illustrating finer details and associations in a nonlinear format. It emphasizes the use of diagrams and pictures that enhance memory and cultivate knowledge (Buzan & Buzan, 1996). And it intends to help facilitate the learning process and promotes the mind’s natural ability of thinking.

Besides, according to cognitive constructivist theory, prior conceptions and knowledge structures are major factors influencing science learning (Ausubel, 1978). This theoretical perspective incorporates, and elaborates upon, a key element of Ausubel’s theory (1978) ‘‘the most important single factor influencing learning is ‘what the learner already knows’’’ (p.10). From this perspective, the usage of mind mapping technique helps students set relations between the new content with their previous knowledge, helping them to form a better understanding of the new content. 

Nowadays, the mind mapping technique is widely used in different areas of education in foreign countries. British educational department has already set mind manager as a required course in elementary and secondary school. In countries like Singapore, Korea, Japan, German and America, educational institutions have also started some academic research in the area of mind mapping; while in universities of Harvard and Oxford, mind mapping is performing its function as not only an important course but also a useful teaching tool. Up till now, mind mapping is widely used in educational practice. 

  If the technique of mind mapping can also be adopted in the vocabulary class in Chinese primary school, we hypothesize that some problems mentioned above about vocabulary retention will be solved. After the test, if the technique of mind mapping is shown to be an effective instructional device for the language learners and more specifically for their vocabulary memory, there will be benefits for both teachers and learners of the new language. This study will contribute to the knowledge base as there is limited previous research about the effect of mind mapping technique on vocabulary memory of students in primary school