The problem of this research was whether or not mind mapping can improve students’ vocabulary mastery. This research was aimed to improve students’ vocabulary through mind mapping. The method of this research was a class room action research. The subject of the research was the students of V grade of SDN 03 Mendelem Belik Pemalang in academic year 2010/2011. There were 32 students in V class which consisted of 13 males and 19 female. The instruments of this research were vocabulary test, observation, questionnaire, and documentation. This research was done for one month (December 2010).
To perform the research, the writer worked collaboratively with English teacher. This research was done based on Kemmis and MC. Taggart’s CAR design. The writer took two cycles which consisted of two actions in each cycle.
Based on the data analyses, it showed the mean of students’ vocabulary was as follows, pre test result was 45,06. Post test cycle 1 result was 55,45, then cycle 2 showed 67,87. Therefore, the improvement of mean was 27,61%, then the observation data showed that the improvement of average students’ vocabulary activity in each cycle was 67,87. Therefore, the improvement of mean was 27,61 %, then the observation data showed that the improvement of average students’ vocabulary activity in each cycle was 47,39 %, and then cycle 2 was77,60%, then the improvement of average in cycle 1 to cycle 2 was 22,88%. The data from questionnaire which consisted of 6 questions, and it showed that 89,06 % of the students gave positive response to the implementation of mind mapping. Those result proved that mind mapping could improve students’ vocabulary mastery for students of V class.