Abstract: The dynamics of matter and energy during the decomposition of Ficus microcarpa leaves are discussed in this paper.The results show that the dry matter of leaves declines during the decomposition of leaf,the theoretical value half-time of leaf decomposition is 101d,it is similar to the tested value；in the first 5 months,the C content changes little,then declines；N concentration increases and the ratio of CKG-1.5mm/KG0.5mmN decreases；the tannin content rapidly decreases at the beginning of decomposition and then keeps stable in the later stage；the soluble sugar content decreases and the crude protein content increases during the decomposition；somewhat the gross caloric value decreases at the beginning of decomposition and then increases at the third and 4th month,and then decreases；theash free caloric value increases with increasing degree of decomposition and then decreases.