采用凋落物分解袋法,研究了在土壤、水分相当的条件下模拟增温对红松(<em>Pinus koraiensis</em>)、蒙古栎(<em>Quercus mongolica</em>)及其混合凋落物分解的影响,以及在不同温度水平下,不同凋落物质量(两种单一凋落物和混合凋落物)的分解特性。利用碱式吸收法测量了凋落物分解累积释放CO<sub>2</sub>动态。将N浓度和C/N率作为凋落物质量参数,用呼吸产生CO<sub>2</sub>的积累值和凋落物质量损失率确定凋落物分解率。结果表明温度升高对单一凋落物和混合凋落物分解均有促进作用,在不同温度水平上,不同质量凋落物的分解特性有所差别,25 ℃和29 ℃条件下混合凋落物分解速率>蒙古栎单一凋落物>红松单一凋落物分解速率。然而,在31 ℃条件下混合凋落物与蒙古栎单一凋落物分解速率相差不大,二者均大于红松单一凋落物分解速率。;Litter decomposition is a fundamental process to ecosystem functioning being responsible of carbon and nutrient cycling. The decomposition of dead leaves depends on both biotic and abiotic factors. The combination of climate (e.g. mean annual temperature (MAT), mean annual precipitation (MAP), actual evapotranspiration, etc) and litter quality (N content, C/N ratio and lignin content) appeared to be the primary controllers of little decomposition. This is particularly true for temperature, which is inextricably linked to other environment parameters as a mutually confounding factor in terrestrial systems. Global average surface air temperature is predicted to increase 1.1-6.4 ℃ over this century. Climate warming is expected to cause species movements and extinctions, change the composition of communities and alter ecosystem functioning. As decomposition depends strongly on temperature, it is expected to be particularly sensitive to climate warming. However, it is still unclear how climate changes influence little decomposition. As global climate changes, it will become warmer and somewhat drier in forest ecosystems, in northeastern China. Changes in global warming and drying could affect forest distribution. The areas of tropical forests and subfrigid forests might increase and that of temperate forests and boreal coniferous forests might decrease, which might affect little quality by altering the structure and species of the original forest communities. The primary temperate forest in northeastern China is dominated by Korean pine (<em>Pinus koraiensis</em> Sieb.et Zucc.) mixed with deciduous species. Many studies showed that <em>Quercus mongolica</em> will become a main associated tree species in broadleaved <em>Pinus koraiensis </em>forest, because it is more conducive to survival under the environment change in future. Therefore, the process of litter decomposition will be affected by climate warming and composition of little species change. Given that decomposition of dead plant tissues in forest ecosystems regulates the transfer of carbon and nutrients to soil, and represents an important source of CO<sub>2</sub> to the atmosphere. It is necessary to carry out research about litter decomposition of the two species under climate change in future. This study used litter bag methods, the whole process use an alkali absorption in a closed chamber method to measured cumulative CO<sub>2</sub> production. We recognized N concentration and C/N ratio as the litter quality parameters, and calculated decomposition rates as cumulative CO<sub>2</sub> production and initial mass remaining. Microcosm experiments under controlled laboratory conditions have proven useful for investigating the various factors that influence litter decomposition. Thus, this study was carried out through a microcosm experiment, in order to:(i) determine the effect of imitate increase temperature on <em>Pinus koraiensis</em>,<em>Quercus mongolica</em> pure and their mix litter decomposition rate and (ii)the effect of litter with different physicochemical properties on litter decomposition rate at the same temperature level under constant moisture condition, during a time period of 151 days incubation in laboratory. Our results suggest that increased temperature accelerated leaf little decomposition rates within both mixed-species litterbags and single-species litterbags. However, its response may vary depending on the level of increased temperature. When the temperature in closed chamber was at 25 ℃ and 29 ℃, decomposition rates within litterbags decreased in the order of mixed-species > single-<em>Quercus mongolica</em> > single-<em>Pinus koraiensis</em>. When the temperature in closed chamber increased to 31 ℃, decomposition rates was faster within mixed-species litterbags and single-<em>Quercus mongolica</em> litterbags than single-<em>Pinus koraiensis</em>, but the variation between mixed-species litterbags and single-<em>Quercus mongolica</em> litterbags decomposition rates was not statistically significant. This study has great significance on understanding of forest ecosystem carbon and nutrient cycle.