Abstract: In order to determine the rate of litter decomposition of Alnus subcordata at two alder stands, litters from Vaz and Asalem with different parent material were collected in autumn. Litters of each region, put in four vases for 7 months in laboratory conditions. Sampling were taken within 21 days. Then nitrogen and carbon was measured in each interval. On the first day, the comparative study between two regions showed that there exits no significant difference between C and N contents of litters. The amount of N was 2.49 and 2.62% in litter of Vaz and Asalem, respectively. The amount of C was 43.4% in Vaz and 39.7% in Asalem. Rate of carbon variation showed no significant difference in two regions. Rate of nitrogen and C/N variation showed significant difference in two regions. C/N of litter reduced from 17.38 to 10.35 and from 15.12 to 10.67 in Vaz and Asalem, respectively.