Mycorrhizal is a the symbiotic association between the roots of higher plants and the mycelium of certain fungi. Mycorrhizal has benefits for improving plant nutrition and increasing growth, as biological protection, involved in the Bio-Geo-Chemical cycle, increasing nutrient absorption from the soil to increase plant resistance to extreme drought and humidity. Research on mycorrhizal spores was carried out in 3 places with high levels of mycorrhizal diversity, humid areas, and lush trees, namely in the forest of the Medan State University campus, Jl. Williem Iskandar, Kec. Medan Tebung City of Medan. This research is limited to knowing the diversity of mycorrhizal spores in the forest of Medan State University. Mycorrhizae observed on the roots of Swietenia macrophylla. Observations focused on the morphology of mycorrhizal spores observed under a microscope. The results showed that the mycorrhizal that were successfully identified and observed around the Medan State University Campus Forest were Gigaspora sp. 1 (10 x 40), Gigaspora sp. 2 (10 x 40), Acaulospora sp. 1 (10x40) Acaulospora sp. 2 (10 x 40), Glomus sp. 1 (10 x 40), Glomus sp. 2 (10 x 40), Glomus sp. 3 (10 x 40), Glomus sp. 4 (10 x 40), Glomus sp. 5 (10 x 40), Glomus sp. 5 (10 x 40), Gigaspora sp. 3 (10 x 40).