This research aims to find out the students’ perceptions about the effectivity of teaching writing through blog. This research is descriptive with the qualitative approach. The number of sample is 47 respondents. The sampling technique used is purposive sampling. The instrument used is questionaire and the analysis technique applied is content analysis. The research result shows that blog can be stated as the effective media in teaching when it is designed with teaching pattern in which the students have been tune in with the blog. The word tune in is that every learnes have known the blog use and how to use it. In principle, the main point to make blog effective as teaching media is the importance of making the students understand the goal and target from the blog use itself as teaching media.