This research aims to find out how to use Modia Word Cards to improve vocabulary mastery of class VII students at SMP Negeri 03 Mempaawah Hilir. The subjects of this research were 30 class VII students. This research was carried out using Classroom Action Research (PTK) which consists of four steps, namely planning, implementation, observation and reflection. The data collection tools are observation, checklist, and field notes. Observation techniques and vocabulary tests for measurement techniques. Then data analysis in this research uses qualitative data and quantitative data to analyze the data. Researchers used two
types of research, namely individual scores and average scores which were used to measure students' vocabulary mastery through the use of Word Card Media. The use of Word Card Media has a significant impact on students. Students
are more active in learning vocabulary using Word Media. The use of Word Card Media can increase students' vocabulary as seen from the results of cycle 1 and cycle 2. The data obtained in cycle I obtained an average score of 55,83 with a level that was still not good. The average test scores show unsatisfactory student scores. The researcher decided to continue cycle II, in cycle II the average score obtained by students was 79,16. With these results, the researcher decided to stop the cycle.

Keyword: Classroom Action Research, Vocabulary Mastery, Word Card Media