ABSTRACTRohmah Ayu Sulistyaningrum. K2213062. A CORRELATIONAL STUDYBETWEEN STUDENTS’ VOCABULARY MASTERY, READING HABIT,AND WRITING SKILL OF THE SECOND GRADE STUDENTS AT MTSNEGERI JUMAPOLO IN THE ACCADEMIC YEAR OF 2016/2017. AThesis, Surakarta: Teacher Training and Education, Sebelas Maret University,October 2017.The aims of the study are to determine the correlation between (1)vocabulary mastery and writing skill; (2) reading habit to writing skill; (3)vocabulary mastery, reading habit, and writing skill.The research was carried out in May 2017 at MTs Negeri Jumapolo. Thepopulation of this research is the second grade students of MTs Negeri Jumapoloin the academic year of 2016/2017. The sampling used cluster random samplingtechnique. The sample was 26 students. In collecting the data, the researcher usedquestionnaire and test. The questionnaire was used to collect the data of students’reading habit, while the test was used to collect the data of vocabulary masteryand writing skill. In analyzing the data, the researcher used Simple Correlationand Multiple Correlation Technique.The result of this study shows that (1) there is a positive correlationbetween vocabulary mastery and writing skill (????????1???? = 0.74); (2) there is a positivecorrelation between reading habit and writing skill (????????2???? = 0.63); (3) there is apositive correlation between vocabulary mastery, reading habit, and writing skill(????????1????2???? = 0.809).In conclusion, this study shows that vocabulary and reading habit are twoimportant factors in improving students’ writing skill. The contribution ofvocabulary and reading habit to writing skill is 65.5%. It means 65.5% of writingskill is determined by vocabulary and reading habit. It indicates that the increaseand decrease of students’ writing skill is in line with vocabulary mastery andreading habit.Keywords: correlation, vocabulary mastery, reading habit, writing skill.