This study aims to determine the feasibility and effectiveness of the supplement book of mycorrhizal spore based on science literacy at the campus forest in State University of Medan that has been developed. The subjects of this research are material experts, learning experts, design experts, and students who take the Lower Level Organism Taxonomy course in the Department of Biology, State University of Medan. Research and development (R and D) with the Thiagarajan (4D) model, namely: (1) Define data taken from the results of student needs analysis and get a score of 69% Students to need mycorrhizal spore supplement books based on scientific literacy, (2) Design the outline of the supplement book produces four chapters that will be discussed, namely, introduction, the development of mycorrhizae in the tropics, methods of observing mycorrhizal and mycorrhizal fungi on mahogany trees in the Unimed campus forest, (3) Development of field research that has been carried out to obtain results. the results of three genera of mycorrhizal spores found under the tree Swietenia mahogany L, namely Glomus sp. with 28 types of spores, Gigaspora sp. with 4 types of spores, and Acaulospora sp. with 3 types of spores. After the observation results are obtained, it is developed into a supplement book that will be tested for feasibility. The results of the material expert assessment obtained a score of 81% in the very worthy category and 95% for the assessment of scientific literacy aspects in the very worthy category, and the results of the learning expert assessment obtained a score of 85.5% in the very worthy category and the results of the design expert assessment obtained a score of 86.6% in the very worthy category. After the book is declared worthy, the fourth stage is carried out. Dissemination (dissemination) is carried out by individual product trials obtaining a score of 87% in the very worthy category, the small group test obtaining a very worthy score of 89%, and the limited group test obtaining a score of 87% in the very worthy category. To prove whether the developed supplement book is effective for use in the Lower Level Organism Taxonomy course, the N-Gain test obtained a score of 63% in the category of quite effective.