The problem in this research is how effective is the use of collaborative learning in improving the writing skills of class X students of SMA Negeri 1 Dolok Merawan in the academic year 2022-2023. The purpose of this study was to describe the effectiveness of the use of collaborative learning in improving the writing skills of class X students of SMA Negeri 1 Dolok Merawan for the academic year 2022-2023. The research method used in this research is the research & development method. The research subject of this development product is the validator. The object of research in this research is a writing learning model, namely a collaborative learning model that is implemented in class X students of SMA Negeri 1 Dolok Merawan in the 2022-2023 academic year. The instrument used to obtain research data using non-test instruments and test instruments. The results of this study indicate that the collaborative learning model is effective in improving the skills of writing descriptive text by class X students of SMA Negeri 1 Dolok Merawan in the 2022-2023 academic year, where before the collaborative learning model development process was in the sufficient category and then increased to good after the learning model development process. collaboratively in class X SMA Negeri 1 Dolok Merawan for the academic year 2022-2023.