This research is attempted to discover the relationship between the independent variable (X) and dependent variable (Y). The hypothesis was tasted there is a significant correlation between students? vocabulary mastery and their reading comprehension. It was conducted in August at the second grade of MAN 19 Jakarta. The writer took the data by using test instrument and did the research with a survey method. The instrument of this research are vocabulary test and reading test. To calculate the correlation between X variable (Vocabulary Mastery) and Y (Reading Comprehension), the writer used Person?s Product Moment Correlation. The result of the analysis shows that the data of the two variables have normal distribution using Liliefors test. The result of normality of the data distribution (X) Lo = 0.110 is smaller than Lt = 0.161 . In scattered diagram, it can be seen that the score has the straight line and linear. From the data analysis, it is known the result of r- observe = 0.552 is bigger than r- table = 0.361. as ro > rt, it can be said that Ho is rejected and Hi is accepted. So, there is a significant correlation between vocabulary and reading comprehension at the second grade of MAN 19 Jakarta. Practically through this study the writer hopes that her research will be useful for those who concerned with English teaching especially in vocabulary and reading comprehension. It can become input to all English teaching to develop better ways of English teaching programme.