ASHFIKAH NUR 2023, The Correlation Between English Vocabulary Mastery and Vocabulary Learning Strategies of EFL Students at Secondary Level of Eleventh Grade at SMAN 3 Samarinda in The Academic Year 2022/2023. S1 Thesis. English Department. Faculty of Teacher Training and Education. Mulawarman University. Samarinda. Advisors: (1) Dr. Hasbi Sjamsir, M. Hum and (2) Dr. Noor Rachmawaty, M. Ed. The present study was aimed to investigate the correlation between students' vocabulary mastery and vocabulary learning strategies. The purposes of this study were as follow: (1) to find out the students’ score of vocabulary mastery achievement of EFL students at secondary level of Eleventh grade at SMAN 3 Samarinda in the academic year 2022/2023; (2) to find out the students’ vocabulary learning strategies of EFL students at secondary level of Eleventh grade at SMAN 3 Samarinda in the academic year 2022/2023; (3) to find out the correlation between students’ vocabulary mastery and vocabulary learning strategies of EFL students at secondary level of Eleventh grade at SMAN 3 Samarinda in the academic year 2022/2023. The design of this study was correlational design within quantitative approach. The sample of this study was 54 of the eleventh grade at SMAN 3 Samarinda in the academic year 2022/2023. The instruments of this research were vocabulary mastery by multiple choices and vocabulary learning strategies questionnaire. The data of this study were analyzed by using Pearson Product Moment Formula. The result of this study showed that (1) the mean score was 57.2, which fell in the category of "Low" level. (2) the mean score was 59.78, which fell in the category of "Fair" level. (3) there was correlation between students' vocabulary mastery and vocabulary learning strategies with N-54, the significant score was .585. It means the correlation between the variables is very weak with no significant. Therefore, it could be concluded that Ha was rejected while Ho was accepted. This research will assist teachers in understanding the correlation between using the best strategy in teaching new vocabulary to increase students' level of vocabulary mastery. In addition, this study also found that the aspects of the English vocabulary mastery learning strategy put forward were very weakly related to English vocabulary mastery. Researcher is looking for other aspects that can influence this; habits, teaching methods and students' English language ability. Keywords: Correlation, Vocabulary Mastery, Vocabulary Learning Strategies