This research aims to find out whether short stories can be successful in improving students' vocabulary mastery or not. The researcher used quantitative research with experimental design using one-group-pretest-posttest. The sample of this research is class XI IPA 2 students of SMA Negeri 6 Palu that consists of 15 students. This class is taken as the experimental class, and the class is taught by using a short story, specifically about the legend. The selection of samples in this research used purposive sampling. After conducting the test, the researcher got the mean score of the students' pre-test is 48.33 while the average score of the post-test is 74.00. Then the data were analyzed using the t-test formula. The result of data analysis shows that t-count was greater than t-table, t-count = 6.282 and t-table = 1.771 at a significance level of 0.05. It can be concluded that there is a significant improving in students' vocabulary mastery after using short stories as learning materials.