Abstract: The present paper deals with the result of the preliminary investigation on the microbiologicalproperties during the decomposition process of forest litters.The experiment was carried outunder laboratory condition.The emphasis was put on the relationships among material transfor-mation,microbiological dynamics and ability of soil metabolism during the decomposition.1.Thedecomposition rate and intensity of forest litters depended on their composition.In the treatmentwith addition of broad-leaves the decomposition rate was quicker than that in the treatment withaddition of the pine-needles.2.In the decomposition of forest litters the release of energy fromsoil and the cycle of nutrient substrates were related to the abundance and succession of soilmicroorganisms,the activities of soil enzymes,the intensity of oxidative metabolism and thechanges of sugar content in organic matter.3.In the carbon cycle of soil the changes of sugarcontent in organic residues and humic substance might be used to predict the direction of energyand material flows in soil ecosystem.