Penelitian ini bertujuan mendeskripsikan perbedaan penguasaan materi antara kelompok siswa yang mengikuti pembelajaran menggunakan materi ajar berbasis STM dan kelompok siswa yang mengikuti pembelajaran menggunakan sumber belajar lain, ditinjau dari keterampilan berpikir kreatifnya. Populasi berjumlah 60 orang siswa kelas X setara SMA dari dua sekolah pendidikan nonformal di Kabupaten Buleleng, dan semuanya digunakan sebagai sampel. Desain penelitian menggunakan Non-equivalent pretest-postest control group. Data dikumpulkan berupa hasil tes penguasaan materi. Data dianalisis menggunakan ANAVA dua jalur dan uji Tukey, dengan taraf signifikansi 5%. Hasil penelitian menunjukkan bahwa kelompok siswa yang mengikuti pembelajaran menggunakan materi ajar berbasis STM memiliki penguasaan materi yang lebih baik dibandingkan kelompok siswa yang mengikuti pembelajaran menggunakan sumber belajar lain, ditinjau dari keterampilan berpikir kreatif. Berdasarkan temuan tersebut, disimpulkan bahwa terdapat pengaruh yang signifikan penggunaan materi ajar berbasis STM terhadap penguasaan materi ditinjau dari keterampilan berpikir kreatif siswa pendidikan nonformal di Kabupaten Buleleng.Kata Kunci : materi ajar STM, penguasaan materi, berpikir kreatif This research aim was to describe differences of student achievement between the groups of student learned by using STM -based teaching materials and and the group of students who learned by using other learning resources, vewed from students creative thinking skills. Population of 60 students of grade X equivalent to senior high school from two school non-formal education in Buleleng district, and all of them are used as samples. Design of research by using non-equivalent pretest-posttest control group. Data were collected in the results of student achievement test that have been validated. Data were analyzed by using two-ways ANOVA and Tukey test, with a significance level of 5%. The research result revealed that there was a difference of studentâs achievement in a better between the group of students who learned by using STM-based teaching materials and the group of students who learned to use other learning resources, in terms of creative thinking skills. Based on these findings, it was concluded that there was a significant effect of the use of the STM -based learning materials on student achievement vewed from students creative thinking skills of non-formal education in Buleleng regency.keyword : STM learning materials, student achievement, creative thinking