Ketersediaan bahan ajar hidrokarbon yang secara eksplisit membelajarkan kemampuan berpikir kritis masih jarang ditemukan. Kondisi tersebut menyebabkan rendahnya kemampuan berpikir kritis mahasiswa calon guru. Penelitian ini bertujuan mengembangkan prototipe berupa bahan ajar model inkuiri dengan strategi konflik kognitif yang valid dan efektif untuk meningkatkan kemampuan berpikir kritis mahasiswa. Penelitian ini merupakan penelitian deskriptif kuantitatif dari validitas dan keefektifan bahan ajar berbasis inkuiri dengan strategi konflik kognitif yang merupakan hasil pengembangan dengan rancangan model ADDIE (Analysis, Design, Development, Implementation, dan Evaluation). Dua validator ahli, satu validator praktisi dan lima mahasiswa dilibatkan pada evaluasi validitas dan keterbacaan bahan ajar. Data penelitian dianalisis secara deskriptif-kuantitatif menggunakan persamaan N-gain. Hasil penelitian menunjukkan bahan ajar yang dikembangkan dinyatakan (1) valid (rerata= 90,31) dengan keterbacaan sangat baik (rerata= 90,22); dan (2) efektif untuk meningkatkan kemampuan berpikir kritis mahasiswa (pretest= 31,3 dan posttest= 61,3) dengan peningkatan medium (n-gain= 0,4). Berdasarkan temuan tersebut, dapat disimpulkan bahwa bahan ajar berbasis inkuiri dengan strategi konflik kognitif dapat digunakan dalam pembelajaran untuk meningkatkan kemampuan berpikir kritis mahasiswa. The Validity of the Hydrocarbon Teaching Materials based on Inquiry Learning Model with Cognitive Conflict Strategies to Improve Critical Thinking Ability Abstract The availability of instructional materials explicitly teaching critical thinking skills is still rare. This condition leads to a low level of critical thinking ability among prospective teachers. This research aims to develop a prototype in the form of an inquiry-based instructional material with cognitive conflict strategy that valid and effective to enhance prospective teachers’ critical thinking ability. This study is a quantitative descriptive research on the validity and effectiveness of inquiry-based instructional materials with cognitive conflict strategy, developed using the ADDIE model (Analysis, Design, Development, Implementation, and Evaluation). Two expert validators, one practitioner validator, and five students were involved in evaluating the validity and readability of the instructional material. The research data were analyzed descriptively and quantitatively using the N-gain equation. The results of the study indicate that the developed instructional material is (1) valid (mean=90.31) with excellent readability (mean=90.22), and (2) effective in improving students' critical thinking ability (pretest=31.3 and posttest=61.3) with a medium level of improvement (n-gain=0.4). Based on these findings, it can be concluded that inquiry-based instructional materials with cognitive conflict strategy can be used in teaching to enhance prospective teachers' critical thinking ability.