ABSTRACTThe aim of this research was to develop and implement biology learning materials based on metacognitive strategy. The learning material was developed by using 4-D model, including the Definition, Design, Develop phase, whereas the Disseminate phase was not conducted because this research is classified as the development research. This research was conducted in one of the senior high schools in East Java. Validating, observing, and giving questionnaire were implemented to collect various information during implementation of the learning materials. The findings from this research showed that the learning materials are valid, practical, and effective in empowering students both in terms of attention and learning outcomes. There were several obstacles occurred during the implementation of the learning materials, i.e. students were confused of new task and learning strategy and were not accostumed in correcting and acknowledged their own mistakes. Alternative solutions were given by providing guidance and information to students about learning using metacognitive strategy, so that students were expected to follow the learning with ease, as well as to train their reflective thinking skill and using an analogy which easier to understand.Keywords: biology learning material, metacognitive, reflective thinking skillsABSTRAKPenelitian ini bertujuan untuk menghasilkan dan mengimplementasikan perangkat pembelajaran Biologi berbasis metakognitif. Pengembangan perangkat pembelajaran menggunakan model 4-D, meliputi tahap pendefinisian (Definition), perancangan (Design), dan pengembangan (Develop), sedangkan tahap penyebaran (Disseminate) tidak dilakukan karena penelitian ini tergolong penelitian pengembangan. Penelitian dilakukan di salah satu Sekolah Menengah Atas (SMA) Negeri di Jawa Timur. Observasi, angket, dan tes digunakan untuk mengumpulkan variasi informasi selama implementasi perangkat pembelajaran. Hasil penelitian menunjukkan perangkat pembelajaran ini valid, praktis, dan efektif untuk melatihkan keterampilan berpikir reflektif. Terdapat hambatan yang ditemui selama implementasi perangkat pembelajaran. Beberapa siswa bingung akan tugas dan strategi belajar baru, dan belum terbiasa mengoreksi dan mengakui kesalahan diri sendiri. Alternatif solusi yang diberikan dengan memberikan pengarahan dan informasi kepada siswa tentang pembelajaran menggunakan strategi metakognitif dengan harapan siswa lebih mudah dalam mengikuti pembelajaran, memberikan bimbingan untuk melatih keterampilan berpikir reflektif, dan membuat analogi yang mudah dipahami siswa.Kata kunci: keterampilan berpikir reflektif, metakognitif, perangkat pembelajaran