This research aimed to find out how can anagram improve students’ vocabulary mastery. The participants of this research were 34 students from XI IPS 3 grade students of
SMAN 2 sintang in academic year 2022/2023. This research used Classroom Action Research (CAR) method, carried out in
two cycles by following the procedure of action research namely planning, implementing, observing and reflecting. Test and observation were made to collect data and analyzed at the end of each cycle. The standard mark for passing is 75 with an achievement percentage of 60%. The results of the first cycle showed that the average score reached 70. 15 students got the highest score (44.00%), 9 students got a good score (26.00%), 3 students got an average score (9.00%), 1 student got poor score (3.00%), and 6 students got a very poor score (18.00%). In the second cycle, the average score reached 82.94, the highest score was obtained by 24 students (70.00%), good grades were obtained by 4 students (12.00%), the average value was obtained by 2 students (6, 00%), 3 students got bad grades (9.00%) and
very bad grades got 1 student (3.00%). Changes in students' enthusiasm and interest in the anagram game were seen
in the second cycle. Meaning that teaching vocabulary using the anagram game can increase students' vocabulary mastery.

Keywords: Improving, Vocabulary Mastery, Anagram