2,021), H0 (nol) ditolak dan H1 (penelitian) diterima. Maka, terdapat perbedaan hasil yang signifikan antara siswa yang tingkat keseringannya tinggi dalam menonton film berbahasa Inggris dengan siswa yang tingkat keseringannya rendah dalam menonton film berbahasa Inggris. Siswa yang memiliki tingkat keseringan menonton film berbahasa Inggris tinggi memiliki pengaruh yang positif terhadap pengusaan kosakata bahasa Inggris dari pada siswa yang tingkat keseringan rendah dalam menonton film berbahasa Inggris. Inggris : PONDIDI, ERHICE. 2010. "The Effect of Frequency of Watching English Movies in Vocabulary Mastery of Students Grade XI SMA Negeri 1 Larangan Brebes Academic Year 2009/2010". Strata 1 Program. Teaching Training and Education Faculty, Pancasakti University Tegal. Key words: The frequency of watching English movies, the vocabulary mastery. The background of this research is the writer wants to know the effect of frequency of watching English movies in the vocabulary mastery of students grade XI SMA Negeri 1 Larangan Brebes The objective of this research is to find out whether the frequency watching English movies has the positive effect in the vocabulary mastery of students grade XI SMA Negeri 1 Larangan Brebes. Based on the theory and frame of thinking the research hypothesis is proposed as follows: "Students who have high frequency in watching English movies getting the better vocabulary mastery than students who have low frequency in watching English movies". Population of this research is students of the eleventh year of SMA Negeri 1 Larangan Brebes which is totally 245 students. Then, the writer selected students who have high and low frequency in watching English movies to be sample of research by score of questioner that consists of the questions that ask about the students' frequency of watching English movies. The writer has used stratified random sampling technique to take the sample of research. There are two groups; each group consists of 30 students. First group is the students who have high score of questioner, while second group is the students who have low score of questioner. The number of the sample is 60 students. The writer used questioner and test as the instruments of the research. Before the writer used the instrument to get data of research, he measured validity and reliability of instrument first. The writer has measured the validity and reliability of test only, because questioner is not used to collect the data, but to group the sample only. Questioner consists of 6 multiple choice questions. The questioners functions to collect the information about students who have high frequency in watching English movies and students who have low frequency in watching English movies. The second instrument is vocabulary test. Vocabulary test consists of 40 multiple choice questions. Vocabulary test is used to measure the vocabulary mastery of students of the sample. Based on the results that have been tested by using T-test formula, T0 is 4,235. The level of significance 5%, on the degree of freedom 58 is 2,021, T0 is higher than Ttable (4,235>2,021), H0 is rejected and H1 is accepted. It means that there is significant effect between students whose high frequency in watching English movies and students whose low frequency in watching English movies. Students who have high frequency in watching English movies have a positive influence to their vocabulary mastery better than students who have low frequency in watching English movie" />