Angelina Kareri Hara Pengarang LAURENSIUS KIAN BERA Dosen Pembimbing 1 SELFIANA P MBADI Dosen Pembimbing 2 Drs. Alexander H. Kabelen, MA Penguji 2 Dr. Drs. Laurensius Kian Bera, MA Ketua Penguji Selfiana P. Mbadi, S.Pd., M.Pd Penguji 1

The purpose of this research is to find out the correlation between vocabulary mastery and writing ability. This study applies random sampling technique where the population is all of the third semester students of English Study Program of Nusa Cendana University and the sample are 30 students. The data are collected by administering vocabulary mastery test and writing ability test. The data are analyzed by using Pearson Product Moment to investigate the correlation between both variables. The result shows that the coefficient between variable X and variable Y is rxy = 0.604. The criteria of correlation between two variables among 0.600 – 0.800 shows a highly correlation. The significant level at 5% is rtable = 0.361, rxy > rtable (0.604 > 0.361). The significant level at 1 % is rtable = 0.463, rxy > rtable (0.604 > 0.463). The result of the analyses shows that there is a significant correlation between vocabulary mastery and writing ability of third semester students of English Study Program of Nusa Cendana University. Therefore, the null hypothesis (H0) is rejected and the alternative hypothesis (Ha) is accepted. In other words, the students who have high score in vocabulary tests tend to have good writing ability. Keywords: vocabulary mastery, writing ability.