In this era, writing is not only based on the paper, but also through social media. There are several studies reveal that social media such as Facebook, Twitter, Instagram, and Line, they could be applied as one of the media to overcome difficulties in writing. It makes the writer interested in conducting a research by utilizing Whatsapp in teaching writing. The objective of this research explained the utilizing the Whatsapp group as an informal channel to teach writing recount texts at the tenth-grade students in SMK Muhammadiyah Purwakarta. The method of this research was the quantitative approach and applied the quasi-experimental. Next, the quasi-experimental design was a non-equivalent control group design. The students’ population at the tenth grade of SMK Muhammadiyah Purwakarta were 103 students, and the samples were 25 students of the experimental class and 20 students of the control class. This research conducted through the following procedures; the first was conducting pre-test to experimental and control class. Next, doing treatment in the experimental class, and the last, performing post-test to experimental and control class. Referring to the research findings, it revealed that the post-test average of the experimental class was 73.44, and the control class was 65.4. The tcount acquired was 3.393 while the ttable was 2.017. It meant Whatsapp gave a positive contribution to students’ achievement in composing recount text. The implication of this research provided useful information about how the procedures or ways to teach writing through social media Whatsapp for the readers, and also to increase students’ interest in writing.