Overall, 3,950 mushroom specimens were collected from the Central Cardamom Protected Forest (CCPF) in Koh Kong province, the Kirirom National Park (KNP) in Kampong Speu province, the Seima Biodiversity Conservation Area (SBCA) in Kratie province, the Mondulkiri Protected Forest (MPF) in Mondulkiri province, the Phnom Bokor National Park (PBNP) in Kampot province, the Western Siem Pang Protected Forest (SPPF) in Stung Treng province, the Ream National Park (RNP) in Sihanoukville province of Cambodia from 2009 to 2014, and then they were identified and classified into 302 species, 165 genera, and 64 families by morphological and genetical characteristics. The mushrooms belongs to Ascomycota were classified into 26 species, 14 genera, and 10 families, while those belongs to Basidiomycota were classified into 276 species, 151 genera, and 54 families, respectively. Among these mushrooms, the most species-rich families are Polyporaceae (26.2%), Marasmiaceae (9.1%), Ganodermataceae (7.7%), Hymenochaetaceae (7.5%), and Mycenaceae (7.1%), and comprised 57.5% of the total specimens identified.