The aim of the research is to find out whether the using flashcards on the teaching vocabulary at the second grade students of SDN Palmerah 25 Pagi West Jakarta can improve vocabulary mastery or not. The study was an experimental study. The total number of population was 40 students. The instruments of the study were a vocabulary test given before and after the treatments, called pre-test and posttest. The position of pre-test is used only to know the first score of students' vocabulary capacity. The score of pre-test was a static score, called Cons6tanta score. It would not be related to other score. The result of post-test in control class was compared with the result of post0test in experiment class. The variables of the study consisting of (1) through flashcards as an independent variables; (2) the dependent variables is Improving students vocabulary. The analysis technique done in this study used T?test. The T-observed result 2.38 bigger than the T?table 1.70. It shows that the mean difference between control class and experiment class is significant. As the t0 > tt, H0 is rejected and the Hi is accepted. Therefore it can be concluded that using lashcards technique in improving students' vocabulary is effective. After doing the treatment, the students feel enjoy involved on the teaching and learning vocabulary, so they not only have receptive vocabulary, but also can arise productive vocabulary without fear and anxiety. It proves that the use of flashcards in teaching vocabulary can improve their vocabulary than teaching vocabulary without flashcards. The benefits of the study are for: The writer: to fulfill the participle program of studying English at University of Muhammadiyah Prof. Dr. HAMKA as the requirement to get the Degree. The students: This research can be used to increase the students' vocabulary achievement. The teacher: to find out which method is more suitable and effective to improve the student's interest in learning English. The school: this research can be used as an item to enrich the inventory of English library.