Writing has become important since the scholar or researcher use writing for spreading new ideas and concepts which is often found in conference presentations, journals, and book publishing. A gap in the research emerges regarding the simultaneous correlation between reading interest and vocabulary mastery with students' writing skills. While individual analyses demonstrate that vocabulary mastery significantly correlates with writing abilities and reading interest does not, an examination of their combined effect on writing proficiency remains unexplored. This gap underscores the need for further investigation into the joint impact of reading interest and vocabulary mastery on students' writing skills to provide a more comprehensive understanding of the factors influencing writing proficiency. This research aims to prove the relationship between reading interest (X1) and Vocabulary Mastery (X2) withstudents' writing ability (Y) in class X at SMAN 4 Kediri.
This study uses a quantitative method to answer the
hypotheses: (1) the relationship between reading interest and students' writing skills (2) the relationship between vocabulary mastery and students' writing skills (3) the relationship between reading interest and vocabulary mastery toward students' writing skills. The researcher used one class for the research respondents. The participants were the X-5 class of SMAN 4 Kediri with a total of 36 students. The instruments used were questionnaires and tests.
The research results show that: (1) there is no significant
relationship between reading interest and students' writing skills, with a calculated Sig. (2-tailed) value of 0.752 > 0.05 (2) there is a significant relationship between reading interest and students' writing skills, with a calculated Sig. (2-tailed) value of 0.000 < 0.05, (3) there is a relationship between reading interest and vocabulary mastery with students' writing skills together, with a calculated Sig. value of 0.000 < 0.05. Although the results indicate no significant relationship between reading interest (x1) and students' writing ability (Y), reading interest may influence other skills such as vocabulary mastery, which indirectly affects students' writing proficiency.

Keywords: Reading Interest, Vocabulary Mastery, students’
Writing Skills