Reading is one of English skills that the students should master well. Reading is a way to get information from the written text. Harmer (2007: 99) stated that, “Reading is useful for language acquisition, the more they read, the better they get. Reading also has a positive effect on students’ vocabulary knowledge, on their spelling and their writing”. One of the reading parts is reading comprehension which is the act of understanding to a text. There are several difficulties that faced by students in teaching reading, such as less vocabulary and different text difficulty level. Based on the result of observation, many students could not determine and felt confused about the main idea of the English text. Therefore, this thesis, entitled: “The Implementation of Numbered Heads Together to Help Students Obtain the Main Idea on An English Text” was intended to find out whether Numbered Heads Together can help students obtain main idea on an English text or not. To achieve the aim of this study, the researcher conducted the research in MAN 4 Aceh Besar. For the sample, the researcher chose second year students of MAN 4 Aceh Besar. To collect the data, the researcher used teaching experiment, pretest-posttest, and questionnaire. Experimental teaching was done in fifth meeting. The result of this research showed that Numbered Heads Together strategy helped students obtain main idea on an English text. It was proved that based on the data from students pretest and posttest score, it was shown that where the students’ mean of pretest was 47,8 and mean of posttest was 76,31. Then, the calculation from ttest also showed the significant improvement of students’ score which is tvalue is bigger than ttable (tvalue is 9,51 and ttable is 1,73). Hence, it can be concluded that the implementation of Numbered Heads Together helped students obtain main idea on an English text.