摘要In order to understand characteristics of substrate quality variationat different litter decomposition stages in subalpine forest, the paper adopted the method ofspatial sequence instead of time successional sequence, three natural layers-Fresh litter layer (L), Fermentative layer (F) and Humus layer (H) were taken as to simulate the different stages of litter decomposition to study water soluble component(WSC), organic solvent soluble component(OSC), acid-soluble extractive(ASE), acid-insoluble residue(AIR) contents and Lignocellulose index (LCI) of four woody species litter, including spruce(Picea asperata), fir(Abies faxonian), birch(Betula platyphylla Suk.) and rhododendron(Rhododendron lapponicum).The result showed that for all the forest litter types, WSC, OSE and ASE contents reduced with the ongoing of decomposition, which leaching quickly at early decomposition stage and slowly in thelater decomposition stage, whereas AIR content and LCI showed a trend of rising with the ongoing of decomposition.For the four litter types, WSC content and OSC content of Pa, Af and Bp in L layer were significantly higher than that of F and H layers, the difference between F and H layers was not obvious.OSC content of Rl were reducing with the ongoing of decomposition process(L>F>H).Forest type had a significant effect on WSC, OSC and AIR contents, whereas it had not significant influence on ASE content and LCI.Generally speaking, WSC and OSC contents of hardwood species were higher than that of conifer species, especially at early decomposition stage, but AIR content of hardwood species was lower than that of conifer species.The result fully shows that the forest type and decomposition stages significantly affected the substrate quality in the litter decomposition process.However, the effects were different among components.These results provided a comprehensive understanding of the litter decomposition process and nutrient cycling in the subalpine forest.