Seasonal production and nutrient concentrations of mushrooms in an Quercus acutissima forest were studied from 1999 to 2000. Thirty 2×2m quadrats were established randomly in the study area. 114 species of mushrooms were identified during the study period. Although mushrooms occurred from May to November in each year, the highest biomass production occurred in August. Seasonal dominant species was Lactarius violascens in June, R. bella and L. violascens in July, Marasmius siccus in August, Cortinarius tenuipes in September, Lepista nuda and C. tenuipes in October, respectively. Annual production of mushrooms in 1999 and 2000 were 84.8 kgDW·ha^-1·yr^-1 and 86.7 kgDW·ha^-1·yr^-1, respectively. Seasonal production was27.1kg/ha for July, 35.9kg/ha for August and 17.1 kg/ha for September, 3.7kg/ha for October, respectively. Seasonal dominant species in biomass was Russula alboareolata in June, R. bella in July, R. pseudodelica in August and September, Lepista nuda in October, respectively. R. pseudodelica showed the highest biomass in the study area, which is 17.5% of the total biomass. Average concentration of nutrients in mushrooms was 45.2mg/g for N, 1.5 mg/g for P, 29.6 mg/g for K, 0.2 mg/g for Ca and 0.8 mg/g for Mg, respectively, which were much higher than those in the leaf litter. Nutrients absorbed by mushrooms in 2000 was 4,163.1 g·ha^-1·yr^-1 for N, 130.1 g·ha^-1·yr^-1 for P, 2,568.2 g·ha^-1·yr^-1 for K, 12.4 g·ha^-1·yr^-1 for Ca, 68.5 g·ha^-1·yr^-1 for Mg, respectively.