Writing is the most complex language skill because it involves various aspects of language; those are spelling, vocabulary, grammar, discourse coherence, etc. Therefore, a learning method that can help students develop ideas independently is needed, which is a project based learning method. This study aims to describe the effectiveness of the application of the project based learning model in improving the skills of writing descriptive English texts of grade VII students of SMPN 6 Denpasar in the academic year 2019/2020. The subjects of this study were 502 of grade VII students. The samples were 46 students in class 7-7 as experimental group and 46 students in class 7-8 as control group which were chosen by using purposive sampling method. This research was a study using a mixed research method. The data collection methods used were library study, tests, observations, and documentation method, while the data analysis methods used were quantitative and qualitative data analysis. Based on testing the effectiveness of the learning model through the N-Gain test, the value of the effectiveness of the learning model obtained was 77% which was categorized as the 'effective' criterion. From the results of this research, it can be concluded that the learning model of project based learning model is effective in enhancing the skills of writing descriptive English text of grade VII students of SMPN 6 Denpasar.