The aim of this research was to improve students‟ reading comprehension to the VIII A grade students of SMP N 4 Kemangkon in the academic year 2012/2013.The method used was Classroom Action Research (CAR) which was designed by Kemmis and McTaggart. The research took two cycles with two actions in each cycle. It started from making planning, acting, observing and reflecting. There were two kinds of data that were collected. There were qualitative and quantitative data. The qualitative data were taken from observation, questionnaire, interview and documentation. The quantitative data were taken from tests (pre-test and post-test). To perform this research, the research worked collaboratively with English teacher in that class. Based on the data analysis, it can be concluded that Think Pair Share could improve students‟ reading comprehension. It was proved by the result of students‟ reading comprehension improvement at the end of Cycle 2, and the improvement of students‟ reading comprehension of test was 85%, in which their score reached the passing grade score of English lesson at SMP N 4 Kemangkon in academic year 2012/2013 which was 65. There was an improvement of students‟ reading comprehension of post-test at the end of Cycle 1 and Cycle 2. In Cycle 1, the mean result of students‟ reading comprehension was 60.83% and in Cycle 2 were81% that the students‟ activeness improved after the implementation of Think Pair Share. Furthermore, most of students gave their positive responses about the implementation of Think Pair Share. It was supported by 95.8% students who gave positive responses in the questionnaire, which meant that the students felt happy to learn reading by using Think Pair Share.