Key words: Teaching Writing, Picture Series Technique. The objective of this study was investigate the effect the teaching writing by using picture series technique to the second grade students of MTsN Kuta Baro, Aceh Besar. This research is an experimental study. There were two classes selected randomly as the sample, namely experimental and control group. For experimental consisted of 26 students, whereas, control group consisted 24 students. The quantitative data was obtained from the result of the pre-test and post-test score was distributed to analyze the result of the experimental result. To analyze the data, statistical formula mean, standard deviation, t-test were used. The result of data analysis can be seen from the result of the post-test for each group in which the mean of the post-test scores of the experimental group is 72,5 while the mean of the post-test scores of the control group is 59,5. By comparing t-test score and t-table score, it shows that the result of the t-test is 4,16 while the result of t-table at a level significant with ? = 0,05 is 2,02. It shows that t-test score is higher that t-table score (4,16 > 2,02). It means that there is a significant different in students writing achievement between the experimental and control group. It can be concluded that students who were taught by using picture series technique have a better performance in writing than those who did not. Thus, the conclusions are alternative hypothesis (Ha) is accepted and null hypothesis (Ho) is rejected.