This research is focused on teaching descriptive text writing by using PowerPoint Presentation. The aim of this research is to know the effectiveness of teaching descriptive text writing by using PowerPoint Presentation to the seventh grade students of MTsN 1 Pontianak in the academic year 2011/2012. It is a pre-experimental study where the form used is one group of pretest and posttest design. The population in this research was all the seventh grade students of MTsN 1 Pontianak in academic year 2011/2012. It involved 32 students from class VIIB as the research subjects. The data were collected by written test and analyzed by ES (Effect Size) formula. The finding show the effect size of treatment (ES) is 2.64. Since the value is higher than 0.5, the effect size of treatments (ES) is categorized as highly efective. It means that teaching descriptive text writing by using PowerPoint Presentation to the seventh grade students of MTsN 1 Pontianak in academic year 2011/2012 gave a significant effect to improve the students achievement
