The background of this research was based on the observation which had been done by the researcher with the English teacher of SMP Nurul Islam Semarang. The result of the observation showed that some of the eighth grade students of SMP Nurul Islam Semarang still have difficulties in reading. It proved when they read the text, they do not understand the content of it. It caused many factors such as the students read rarely, and they have problems in acquiring vocabulary. They were unable to use context clues to guess words, and when they find difficult words they tend to ignore the words and its make them stop reading. Finally, they cannot answer the questions based on the text. It could make the teaching and learning process was monotonous and the students were uninterested and unmotivated in learning reading. Based on those facts, this research was conducted to overcome the problems by using a story map as a medium to improve the students’ reading comprehension in narrative texts. Story map can help the students comprehend narrative texts easily because it provides a graphic or schema to put the chronological events of the story and other elements of the text. This research was a Classroom Action Research (CAR) and done in two cycles. The participants were the VIII A students of SMP Nurul Islam Semarang in the academic year of 2015/2016. This research has two purposes; to prove the implementation of story map in teaching narrative texts can improve students’ reading comprehension and to describe its improvement. After collecting the data, the result showed the improvements of the students. Students’ mean score of reading in the last semester was 65; this score hadn’t met the minimum standard score yet (72). The students’ mean score in cycle 1 was 67. Therefore, second cycle was conducted. The students’ mean score in cycle 2 increased became 89 or 87.5% students, who achieved minimum standard score. So, the objectives were reached. Based on the result, it could be concluded that the implementation of story map can improve students’ reading comprehension in narrative texts at the VIII A grade of SMP Nurul Islam Semarang in the academic year of 2015/2016.