Abstract: The chemical properties of litter layer under major coniferous forests in Northern China are studied. The results have been shown as follows.(1)significant difference has been found between chemical properties of L layer and F layer. Various mineral elements and coarse protein tend to be accumulated in F layer.(2)the content of inorganic, organic substances in litter layer and their properties vary significantly with different tree species.(3)the decomposition rate of litter is generally lower under coniferous forests. Large amount of nutrients, coarse protein and cellulose are detained in F layer.(4)within stands investigated, the hig hest decomposition rate of litter appears under Platycladus orientalis forest, and the lowest one appears under Picea wilsonii forest.

Key words: soil respiration, root respiration, litter layer CO2 release, root-free soil CO2 release, Q10 value, temperature sensitivity