The objectives of the research were to know the implementation of Concept Attainment Model in improving student’s vocabulary mastery in recount text and to find out whether there was any significant difference of vocabulary mastery between students who were taught by using Concept Attainment Model and students who were taught without using Concept Attainment Model at MTs N 3 Bangka in academic year 2018/2019.

In this research, the researcher limited the study in vocabulary mastery especially for noun, verb, and pronoun. The type of the text used in this research was recount text that focused on personal recount text. This research was quantitative with quasi-experimental design. The population of this research was the whole class of VIII grade students, VIII A, VIII B, and VIII C with total number 65 students. Then, the sample of this research was VIII B and VIII C which is determined by using purposive sampling. Based on the result of observation, most of students in experimental group had a progress in every aspects of observation such as cooperation, participation, and concept (product). Next, the result of independent sample post-test of experimental and control group found that t-obtained in equal variances assumed was 3.536. Comparing the t-obtained 3.536 and t-table was 2.02 and degree of freedom was 40. Since p-output or the significant (2-tailed) was .001 lower than computation with level significant 0.05 and t-obtained 3.536 was higher than t- table 2.02. It means that there was a significant difference between the post-test in experimental and control group. Therefore, the implementation of Concept Attainment Model could motivate students to fulfill all aspects of observation effectively.

In conclusion, the result showed that the null hypothesis (H0) was rejected and alternative hypothesis (Ha) was accepted. It means that there was significant improvement of students’ vocabulary mastery by using Concept Attainment Model. Hopefully, this thesis will be beneficial for those who read and experience in the field of education.