The objectives of this research were to find out the effectiveness of using Word Expert Strategy in teaching vocabulary to the first grade students’ of SMKN 2 Bungoro Pangkep Regency. This research employed quasi-experimental design with two group pre-test and post-test design. There were two variables in this research; they were independent variable (The Effectiveness of Using Word Expert Strategy) and dependent variable (Students Vocabulary). There was kind of instrument in this research, that was test. Test was used in pre-test and post-test. The data indicated that there was a significant difference between the students’ post-test in experimental class and that in control class. So, the researcher concluded that using word expert strategy was effective in teaching vocabulary