Climate change has an important impact on snow and snow cover in the mid latitude region of the world,and the contribution of soil respiration to regional and global carbon cycles is more important in winter. The effects of snow cover and water content on the short - term CO_2 fluxes during freeze - thaw cycles were evaluated for the undisturbed soil columns of Typical Alpine Wetland and farmland grey desert soil outdoors in winter. Our results showed that the dynamics of soil CO_2 fluxes during the freeze - thaw cycles were affected by snow cover and soil organic carbon content. Soil CO_2 emissions generally enhanced during the first freeze - thaw cycle, and gradually decreased with successive cycles. The increase of snow cover thickness delayed the CO_2 emission peak in the early stage of freezing and thawing process. In addition,there was a significant difference in the average CO_2 emission rate between HW1_0 and HW1_(30) treatments (P < 0.05) under the condition of initial soil saturated water content of 20 - 30%,and when the snow thickness was increased,the CO_2 emission from two soils showed a significant positive correlation with the ground surface,the atmosphere and the temperature of 5cm soil layer respectively(P < 0.01). Snow cover thickness had no significant effect on the average CO_2 emission rate of farmland and wetland soil (P > 0.05) under the condition of initial soil saturated water content of 50 - 60%, However,CO_2 emission from farmland soil snow cover treated with 30cm and wetland soil snow cover treated with 15cm was significantly positively correlated with soil surface temperature and soil temperature at 5cm (P < 0.01),but not significantly affected by atmospheric temperature. The above results suggest that the seasonal change of the snow has an important impact on short - term soil CO_2 emissions in the arid area because of climate changes.