Penelitian ini bertujuan untuk menghasilkan prototipe Buku Guru dan Buku Siswa berbasis Contextual Teaching Learning (CTL), mendeskripsikan validitas, mendeskripsikan kepraktisan, serta mendeskripsikan keefektifan dari prototipe tersebut. Jenis penelitian yang digunakan adalah penelitian pengembangan yang mengacu pada educational design research oleh Tjeerard Plomp & Nieveen menggunakan model 4D oleh Thiagarajan, meliputi tahap define, design, develop dan disseminate. Buku Guru dan Buku siswa diuji coba pada 33 siswa. Hasil uji coba dianalisis secara deskriptif kualitatif. Hasilnya sebagai berikut: 1) Validitas Buku Guru, Buku Siswa dan tes penilaian berpikir kritis dengan kategori “valid”. 2) Kepraktisan Buku Guru dan Buku Siswa sangat praktis dilihat dari modus keterlaksanaan pembelajaran, keterbacaan Buku siswa dengan kategori “mudah”. 3) Keefektivan pembelajaran sangat efektif dan mengalami peningkatan dilihat dari tes keterampilan berpikir kritis. Respon siswa memberi respon positif. Berdasarkan hasil-hasil tersebut maka dapat disimpulkan bahwa prototipe buku guru dan buku siswa sangat layak diterapkan dalam proses pembelajaran karena untuk meningkatkan keterampilan berpikir kritis.

Intended research design to produce a prototype of a Teacher's Book and a Student Book based on Contextual Teaching Learning (CTL), describes validity, practicality, and the effectiveness of the prototype. The research procedure used by the researcher refers to Educational design research using the 4D model comprising the phases of define, design, develop and disseminate. Teacher's books and student books were tested on 33 students. The trial results were analyzed descriptively qualitatively. The results are as follows: 1) The validity of Teacher's Books, Student Books and critical thinking assessment tests with the "valid" category. 2) Practicality of Teacher's Books and Student Books is very practical in terms of the mode of implementation of learning, readability of student books in the "easy" category. 3) The effectiveness of learning is very effective and has seen improvements in the test of critical thinking skills. Student responses gave positive responses. Based on these results it can be concluded that the prototype of the teacher's book and the student's book are very feasible to be applied in the learning process because it enhances critical thinking skills.