Vocabulary is one of important basic skill must be taught to the students in teaching and learning English. Vocabulary is essential for effective comunication,vocabulary become one of the most important aspects of language skill because people have to master numerous vocabularies in order to improve their language skills. The problems in this research were: first, some students can not understand English well because of lack of vocabularies; second, some students do not activein learning process and third, teacher teaches vocabulary monotonously by asking students to memorize vocabulary. The purpose of this research is to find is there any significant effect of using word detective strategy in teaching vocabulary at the eighth grade Students of SMPN 11 Kerinci Academic year 2019/2020. The population in this research is all students at eight grade of SMP 11 Kerinci (87students). Samples in this research were class VIII A as control class that taughtby using lecturing strategy and class VIII C as experiment class were taught by using Word Detective Strategy. The sample is determined by using random sampling technique. The instrument in this research was vocabulary test. The simple regression model in this research was analyzed by using SPSS program (Statistical Product and Service Solution) 23.00 for window and Ms. Excel 2010. The data is analyzed by using regression linier, the formula was T-test. The result of the research, it was gotten Sig. 0,004 < 0,05 and t count 9,847 > 1,699 t-table.It can conclude that hypothesis H1 is rejected and H0 is accepted. It means there is significant Effect of Using Word Detective Strategy in Teaching Vocabulary at the Eight Grade Students’ of SMPN 11 Kerinci Academic Year 2019/2020. Therefore the researcher suggested for English teacher to apply the Word Detective Strategy in teaching vocabulary, The students are suggested to be able to follow the classroom activities that use the Word Detective Strategy in learning vocabulary and next researchers are suggested to use the Word detective Strategy to be researched in different English skills in different place.
