Mushroom survey and collection were conducted in the Phousabous National Protected Area (PNPA), which is located at the Northeastern area 230km from the capital city of Lao-PDR, Vientiane, from April 2017 to September 2018. During this periods, mushroom specimens were collected from 8 different locations, and then they were identified and classified into 284 species, 142 genera, 56 families, 20 orders and 7 classes by morphological and molecular analyses. The mushrooms belongs to Ascomycota were classified into 10 species, 5 genera, 5 families, 4 orders and 3 classes, while those belongs to Basidiomycota were classified into 274 species, 137 genera, 51 families, 16 orders, and 4 classes, respectively. Among these mushrooms, the most species-rich families are Boletaceae (16.06%), Polyporaceae (10.12%), Russulaceae (9.94%), Amanitaceae (7.68%), Agaricaceae (4.54%), Marasmiaceae (4.36%), Cortinariaceae (3.66%), Entolomataceae (3.66%), Mycenaceae (2.79%), Xylariaceae (2.44%), Physalacriaceae (2.09%), Omphalotaceae (2.09%), Hydnangitaceae (2.09%), Lyophyllaceae (1.92%), Tricholomataceae (1.75%) and comprised 75.19% of the total specimens identified.