In order to determine the rate of litter decomposition of Carpinus betulus at two hornbeam stands, litters from Vaz and Asalem with different parent material were collected in autumn. Litters of each region, put in four vases for 357 days in laboratory conditions. Sampling was taken within 21 days. Then nitrogen, carbon and phosphorus were measured in each interval. On the first day, the amount of N was 1.13% and 1.32% and amount of phosphorus was 1857.5 mg/kg and 1885 mg/kg in litter of Vaz and Asalem repectively. The amount of C was 43.38 % in Vaz and 41.12 % in Asalem. Rate of carbon variation showed significant difference in two regions. Rate of Nitrogen and phosphorus variation showed significant fifference in two regions. C/N of litter reduced from 38.39 to 18.21 and from 31.15 to 18.50, C/P of litter reduced from 232 to 163 and from 226 to 178 in Vaz and Asalem respectively.
