abstractAyu Fatimah 2013.  Developing students’ writing ability in business letter by using flashcard (A research conducted of the students at SMKN 1 Batudaa). Skripsi English Department, Letter and Culture Faculty, Gorontalo State University. Guide by Titien F. Mohammad, S.Pd.,M.App.Ling as adviser I and Miss Sri Rumiyatiningsih as adviser II.The aims of this research are to know the result study of student’s ability in writing business letter by using flashcard. The researcher just focused on the part of the business letter as the indicator of analyzed the data. Samples of this research in class X1 Akuntansi which has 30 students in SMK 1 Batuda’a.This research used quantitative method the design of research is quasi experiment just take one class. The researcher gives pre-test, treatment, post-test. To analyzing the data the researcher have conducted use T-Testing and verifying the hypothesis. The result of this research shows that using flashcard was help the students to write a good business letter. In this case, the researcher found that the highest score of students’ ability in writing business letter before treatment is 16,67 % and the increasing of highest score of students’ ability after treatment is 26,667%. Then the hypothesis in this research was tenable. After doing the calculation, the hypothesis accepted because   t_count bigger than t_list that is 14,12752 bigger than 2,045. Therefore, researcher concluded that this media could develop students’ ability in writing business letter.Key word: Writing ability, Flashcards, Business letter.