Abstrak Buku ajar menulis teks deskripsi yang ada belum melatih siswa menulis teks deskripsi sesuai harapan kurikulum Merdeka. Maka, perlu dikembangkan buku ajar menulis teks deskripsi berbasis pedagogi genre. Untuk itu, tujuan penelitian ini mengembangkan buku ajar menulis teks deskripsi berbasis pedagogi genre pada siswa kelas VII SMP Negeri 22 Kota Bengkulu. Penelitian ini termasuk jenis penelitian ADDIE. Teknik pengumpulan data menggunakan dokumentasi, wawancara, angket, observasi, dan tes. Teknik analisis data menggunakan uji kelayakan dan uji N-gain (g). Hasil penelitian menunjukkan bahwa buku ajar menulis teks deskripsi berbasis pedagogi genre layak dan efektif digunakan oleh siswa. Hal ini dibuktikan dengan hasil kelayakan dari segi materi, bahasa, dan desain. Kemudian dari hasil uji efektivitas menunjukkan buku ajar menulis teks deskripsi berbasis pedagogi genre mampu meningkatkan kemampuan menulis teks deskripsi dari nilai rata-rata pretes 59,4 menjadi 80. Buku ajar menulis teks deskripsi berbasis pedagogi genre memiliki 4 langkah, sistematika dimulai dari membangun konteks menulis teks deskripsi, pemodelan, mengkonstruksi teks deskripsi bersama, dan mengkonstruksi teks deskripsi secara mandiri. Kata kunci: Pengembangan Buku Ajar, Menulis Teks Deskripsi, Model Pedagogi Genre Abstract Existing textbooks for writing descriptive texts have not trained students to write descriptive texts according to the expectations of the Merdeka curriculum. So, it is necessary to develop a textbook for writing descriptive texts based on genre pedagogy. For this reason, the aim of this research is to develop a textbook for writing descriptive texts based on genre pedagogy for class VII students at SMP Negeri 22 Bengkulu City. This research is a type of ADDIE research. Data collection techniques use documentation, interviews, questionnaires, observations and tests. Data analysis techniques use feasibility tests and N-gain (g) tests. The results of the research show that textbooks for writing descriptive texts based on genre pedagogy are feasible and effective for use by students. This is proven by the feasibility results in terms of material, language and design. Then, the results of the effectiveness test show that the textbook for writing descriptive text based on genre pedagogy is able to increase the ability to write descriptive text from an average pre-test score of 59.4 to 80. The textbook for writing descriptive text based on genre pedagogy has 4 steps, systematically starting from building the context for writing descriptive text, modeling, constructing descriptive text together, and constructing descriptive text independently. Keywords: Textbook Development, Writing Description Texts, Genre Pedagogical Models