Tujuan penelitian pengembagan ini adalah untuk menghasilkan buku ajar inkuiri terbimbing pada materi perubahan lingkungan dan daur ulang limbah untuk melatihkan keterampilan berpikir kritis siswa SMA kelas X yang layak secara teoritis dan empiris. Pengembangan buku mengadaptasi metode 4D yaitu define, design, develop dan menghilangkan tahap dessiminate. Pengembangan buku bertempat di Jurusan Biologi, Universitas Negeri Surabaya dan percobaan terbatas pada 12 siswa di SMAN 1 Gedangan. Penelitian dilakukan selama semester genap tahun 2018/2019. Data yang diperoleh dianalisis secara deskriptif kuantitatif. Kelayakan teoritis diperoleh dari hasil validasi oleh tiga ahli dengan skor rata-rata 3,8 termasuk dalam kategori sangat valid, keterbacaan menunjukkan level 10 sehingga telah sesuai untuk digunakan sebagai buku ajar kelas X SMA, respon siwa menunjukkan kategori positif dengan presentase 99%, dan analisis hasil latihan keterampilan berpikir kritis menunjukkan hasil 81% dengan kategori efektif, disimpulkan buku ajar telah dapat melatihkan keterampilan berpikir kritis.
Kata kunci : Pengembangan, Inkuiri terbimbing, Perubahan lingkungan dan daur ulang limbah.

The purpose of this development research is to produce guided inquiry teaching books on environmental change material and waste recycling to train the critical thinking skills of high school students of class X who are feasible theoretically and empirically. The book development adapted the 4D method, namely define, design, develop and eliminate the dessiminate stage. Book development took place in the Department of Biology, Surabaya State University and the experiment was limited to 12 students at SMAN 1 Gedangan. The study was conducted during the even semester of 2018/2019. The data obtained were analyzed descriptively quantitatively. Theoretical feasibility obtained from the results of validation by three experts with an average score of 3.8 included in the very valid category, readability indicates level 10 so that it is suitable for use as textbooks for high school class X, the response of the students shows a positive category with a percentage of 99%, and the analysis of the results of the exercise of critical thinking skills showed 81% results in the effective category, concluded that textbooks could train critical thinking skills.
Keywords: Development, Guided Inquiry, Environmental Change and waste recycling.