| Forest litter was main component of forest ecosystems, it was very important for the forest ecosystems to remain its structure and function. Litter was the bases of improving soil structure, it was a main indicator of soil fertility, and it had an important meaning to soil and water conservation.This paper was doing the research on the trend and law of nutrient emancipation of Inner Mongolia Greet Xingan Mountains of litter in natural forest Larix Gmelinii, and found out the result from changing trend of litter, process of litter decomposition, and changing of nutrient contents. The result showed that:1. During 2006～2007, amount of the litter fall of Larix Gmelinii was 1886.38kg·hm-2·a-1, in 2007～2008, it was 3222.64 kg·hm-2·a-1, and leaf litter make up 62% and 66% in the total amount of litter fall. The proportion of component of litter was: leaf > braches > cones > barks, the storage amount of un-decomposing and sub- decomposing layer were analyzed by investigating the remnant litter under the forest. The result showed that Larix Gmelinii forest total storage amount was 9695.74kg·hm-2, the storage amount was 4767.43 kg·hm-2 in un-decomposing layer and was 4928.323 kg·hm-2 in sub-decomposing layer.2. The litter throughout the year appeared an obvious trend of single-peak curve in Larix Gmelinii. In September, the input amount of litter accounted for 62 66% of the annual total amount of litter. The phenomenon of deciduous occurred during the whole year, but it has the maximum time of deciduous in September .The value of peak of braches, cones, and barks appear in May to June.3. The decomposition of Larix Gmelinii was very slowly, after one and a half years decomposing, the change of Weightlessness ratio was only 2.8～10.3%. The Decomposion ratio of Larix Gmelinii were: leaf0.0548 g·g-1·a-1,branches0.0387 g·g-1·a-1,cones 0.0162 g·g-1·a-1.4. The characteristics of nutrient retranslation showed two modes, emancipation and direct emancipation. Through decomposing of 548d, the sequence of content of N goes as follows: leaf>braches>cones, and the content of P was in the same sequence, but the sequence content of Ca,Mg was: branches>leaf>cones, branches>cones>leaf. With the decomposition of litterfall, C/N reduced gradually at the beginning, then reduced quickly and reduced smoothly at last.5. The concentration of N was the highest one in the component of litter (Larix Gmelinii), and P was the lowest one. The sequence of elements return: N>K>Mg>Ca>P, N had the highest nutrient return. It accounted for 63.3%, 68.6% in total nutrient in litter returning. P accounted for 1.1%, 0.8%; K accounted for 27.8%, 26.5%; Ca accounted for 2.5%, 1.9%; Mg accounted for 5.3%, 2.2%. And the amount of return of Ca closes to Mg. The sequence of litter component was: branches>cones>leaf.6. The process of litter decomposition was highly affected by soil temperature and soil microbial. The positive correlation between weightlessness ratio and soil temperature, soil microbial did achieve significant.
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