This study discusses a comparative study of group-based learning method between STAD and SGD toward students’ writing achievement of descriptive text on the tenth grade of SMK Salafiyah Kajen in the academic year of 2017/2018. The purpose of the study was to differentiate those two methods which then found the appropriate method between STAD and SGD for learning writing skill. This study used mixed method by using comparative design. The subject of this study were the students at the tenth grade of SMK Salafiyah Kajen, students class RPL 2 and TB. The students from both of the class had different treatment which RPL 2 was treated using SGD and TB was treated using STAD. The technique of data collection were test, observation and documentation. The test consisted of two tests, they were pre-test and post-test. After collecting the data, it was found that the average score of pre-test of SGD group was 50.06 and for STAD group was 47.75, meanwhile, the average score of post-test of SGD group was 68.70 and for STAD group was 63.10. So, the computation of t count was 5.031 and the t table was 1.69. The t count was higher than t table, which stated that Ha was accepted. It meant that there was significant difference between students’ writing achievement which was taught by using STAD and SGD. The conclusion defined that SGD was better than STAD to be applied in learning writing.