Leaf litterfall,litter decomposition and nutrient return through litterfall of three dominant species,i.e. Quercus serrata,Schima wallichi and Lithocarpus dealbata were studied in different months throughout the year to assess the input and release of nutrient in the forest soil of a sub-tropical mixed oak forest of Manipur,northeastern India. Oaks in northeastern region of India are economically important species for the production of Tasar silk. The monthly litterfall ranged from 25.6 g·m-2 (July) to 198.0 g·m-2 (February) and annual litterfall was 1093.8g·m-2 in the forest site. At initial month (on November 3),the concentrations of N and C were the highest in L. dealbata,followed by Q. serrata and lowest in S. wallichi,whereas lignin and cellulose concentrations at initial month were the highest in S. wallichi,followed by Q. serrata and L. dealbata. L. dealbata (k =0.54) exhibited a high rate of litter decomposition,coinciding with high concentrations of N and C and low cellulose in the litter at initial month. However,low rate of litter decomposition in S. wallichi (k = 0.33) coincided with low value of N and C and highest value of lignin and cellulose at initial month. The remaining biomass in different months was positively correlated with the lignin,C,C/N ratio and cellulose,but it negatively correlated with nitrogen concentrations at initial month. The rate of litter decomposition was the highest in rainy summer months,owing to congenial environmental conditions and lowest rate of litter decomposition in cool and dry winter months.