Students tend to think that Biology is a complicated lesson. This is caused by the abstractness of Biology concepts, with so much material that makes students easily bored and difficult to digest the learning. Therefore, effective biology learning methods are needed so that teaching and learning activities become more interactive. Learning media that is suitable for the needs of the learning process are digital books or flipbooks. By creating and developing a digital book, it is hoped that students will be more active and enthusiastic in participating in learning. This research aims to determine the feasibility of flipbook-based learning media on the biology of the circulatory system. This research uses the R&D (Research and Development) method with a 4D model (Define, Design, Develop, Disseminate). However, this research was only carried out until the development stage. The readability test was carried out on class XI MIPA students at Bintang Timur High School, Ruteng, Manggarai, East Nusa Tenggara. Data collection used interviews with teachers, expert validation, readability test questionnaires, and teacher and student response questionnaires. The data analysis technique used is descriptive analysis and calculation of the percentage of validation results, readability tests, and student responses. The results of the validation from media experts and material experts obtained a percentage of 78.46% and 62.85% with the "Fine" criteria. Meanwhile, the results of the response or readability test for teachers and students obtained a percentage of 95.38% and 94.25% with the criteria "Very Eligible". The conclusion is that the digital flipbook-based learning media on the circulatory system material is declared valid and suitable for use in the learning process.