This research is aimed (1) to investigate reading habits of the students of English Education Department of Universitas Muhammadiyah Yogyakarta (EED UMY) batch 2015, (2) to reveal the grammatical mastery of EED UMY students, and (3) to find the correlation between students’ reading habit and their grammatical mastery at EED UMY batch 2015. This study is correlational design. The data were collected from 102 students of EED of UMY batch 2015 using a questionnaire and test. The test consists of 25 grammar items while the questionnaire consists of 25 items.The data were analyzed using descriptive statistics and inferential statistics computed in SPSS 22. The findings show that students’ reading habit of EED of UMY is 36.38, which indicate a moderate category (28.4 – 36.6). Whereas, the finding of grammatical mastery indicates 38.08 (≤ 27 – 38.3). It means that students’ grammatical mastery is in low level. The correlation between reading habit and grammatical mastery is value 0.077 and significance level 0.441. It indicates that, the correlation between both variable is low or almost have no correlation and it is followed by low significance level. From the result, the researcher concludes that the increasing reading habit is not followed by students’ grammatical mastery.