Sari, Danty Setia Tanjung. Abstract. 2017. The lack of learning resources and references used in the learning process has affected students having difficulty obtaining maximum feedback. This is supported by several evidences, one of which, there is no strengthening mechanism in delivering materials in Power Plant Subject. Power plant is one of the subjects in the Department of Electrical Engineering that learns various types of power plant such as: Hydroelectric Power Plant (PLTA), Diesel Power Plant (PLTD), Steam Fired Power Plant (PLTGU), Solar Power Plant (PLTS), Nuclear Power Plant (PLTN), and Geothermal Power Plant (PLTBB). This research only concerns on Geothermal Power Plant. Another evidence of students’ difficulty to obtain maximum feedback is students do not have a reference book as supporting material in learning process. The purpose of the reference book is to facilitate teachers in delivering materials and providing interesting materials for students. The problem has obtained through the results of a pre-research questionnaire to 71 students of Electrical Engineering Education 2014. The purpose of this research and development is to design, develop, and test the feasibility of PLTPB textbooks for Power Plant Subject, Department of Electrical Engineering, Faculty of Engineering, State University of Malang. This research and development uses Sugiyono’s R&D (Research and Development) model with 10 stages: (1) potential and problems, (2) data collection, (3) product design, (4) design validation, (5) (6) product trials, (7) product revisions, (8) usage trials, (9) product revisions, and (10) mass products. The mass product in this research and development produces reference books that can be produced as needed. The result of research and development of reference books are completed with: text, images, material presentation (illustrations, concept maps, summaries, formative form, and glossary). This research is validated by Electrical Engineering Lecturer State University of Malang and tested over Electrical Engineering S1 2015 students offering A and B. The result of validation test of reference book by both validation team has managed to get the 81,61% (valid enough) percentage of validity, 85.00% (very valid) test result of the product, and 86.75% (very valid) of the trial usage. Based on the accumulation of the score, it is shown that the Geothermal Power Plant reference book is valid, so it is applicable to be used in the learning process.