Utilization of litters and understory shrubs at forest floor is a hot issue of renewable forest biomaterial exploitation in future; however, the influences on soil respiration and soil property from this utilization are still undefined. Aiming to estimate how forest floor cleaning affect the carbon budget, a 2-years measurement was carried out with a Li-6400 system and soil physical parameters of soil bulk density, capillary porosity, soil temperature and soil volumetric moisture were also measured in a Larix gmelinii plantation. Firstly, forest floor cleaning evidently decreased soil respiration. The 2-a mean value reduced from 2.20 μmol·m-2s-1 at unclean control to 1.18 μmol·m-2s-1 at the cleaning plot. Similarly, annual cumulative soil CO2 emission decreased from 44.2 μmol·m-2a-1 to 22.4μmol·m-2a-1. Q10 value for soil respiration in the cleaning plot (2.22) was lower than that in control plot(2.33), and R0 value were 0.61, 0.36 μmol·m-2s-1 in the cleaning and control plots, respectively. Secondly, cleaning practice at forest floor slightly increased the soil temperature at the vegetative season, but reduced it at the dominant season of winter. The cleaning practice made soil moisture higher in summer, but lower in spring and autumn, which induced a much wider range at the cleaning plots. Moreover, the soil bulk density at the cleaning plot was 53% higher (p<0.05), the soil non-capillary porosity and soil capillary porosity was respectively 49.5% and 15% lower (p<0.001) than that at the un-cleaning control plot. Thirdly, forest floor cleaning of litters and understory shrubs could make a loss of carbon about 175.0 mol·m-2. This loss decreased from 175.0 mol·m-2 to 137.4 mol·m-2 when considering the decrease in soil respiratory carbon loss. Therefore, both utilization of biomaterial of litters and shrubs at forest floor and decrease in CO2 release from the cleaning practice could mitigate the global warming pressure from utilization fossil fuel. However, the alteration of soil physical characters should be carefully considered since this alteration was not favorable to growth of the larch plantation and stability of larch ecosystem in a long run.