<![CDATA[The aim of this research was to figure the effect of using problem-based worksheet to studentscritical thinking skill. The design of research design was pretest and posttest with non-equivalent group. The subject of this research were students in class VIIG and VIIEof SMPN 21 Bandar Lampung, chosen by purposive sampling. The research data were quantitative data which was obtained from pretest, posttest, and N-gain which was analyzed by t-test and U-test and qualitative data which was students' critical thinking skill from observation of learning activities and questionnaire responses of using problem-based worksheet. The results of research showed that students critical thinking skill in experiment class was significantly different by average of N-gain was 65,7. Therefore, it can be concluded that using problem-based worksheet can improve students critical thinking skill.Tujuan penelitian ini untuk mengetahui pengaruh penggunaan LKS berbasis masalah terhadap kemampuan berpikir kritis (KBK) siswa. Desain penelitian yang digunakan adalah pretes-postes kelompok tak ekuivalen. Subjek penelitian ini adalah siswa kelas VIIG dan VIIEdi SMPN 21 Bandar Lampung yang dipilih secara purposive sampling. Data kuantitatif diperoleh dari nilai pretes, postes, dan N-gain yang dianalisis menggunakan uji t dan uji U. Data kualitatif diperoleh dari aktivitas belajar siswa, dan tanggapan siswa terhadap LKS berbasis masalah. Hasil penelitian menunjukkan KBK siswa kelas eksperimen berbeda signifikan dengan rata-rata N-gain sebesar (65,7). Dengan demikian, dapat disimpulkan bahwa LKS berbasis masalah dapat meningkatkan KBK siswa.Kata kunci: kemampuan berpikir kritis, LKS berbasis masalah, peran manusia dalam pengelolaan lingkungan]]>
