The objective of this research is to explain the effectiveness of using “Board Game” to teach modal expressions of ability and willingness. The population of this research are eighth grade students. The total of them is 325 students. The research method was an experimental research which involved two classes, they were experimental class and control class. The VIII F class was chosen as experimental class which was taught by using Board Game and the VIII G class was chosen as control class which was taught by using cooperative learning method. The experimental and control class were given pre-test and post- test. Before giving pre-test, the researcher gave try-out test to VIII A class to find out the validity instrument, the reliability instrument, the difficulty level, and the discriminating power. The formula used to analyse the data was t-test. It was used to determine whether there was a significant difference between students’ score of the experimental class and control class or not. Based on the calculation t-test was obtained t count: 2.411 and t table: 1.671. It shows that t count > t table (2.411 > 1.671). It means that Ha was accepted while Ho was rejected. Since t-test score was higher than t table, it means that Board Game was an effective medium to teach teach modal expressions of ability and willingness at the eighth grade of MTs Mathalibul Huda Mlonggo Jepara in the academic year of 2019/ 2020.