| The study area of this research is the Xilinguole grassland and the Hulunbeir grassland. Choose the typical snow field as the pilot and take these snows which thickness are 50cm, 40cm, 30cm, 20cm and 10cm as the treatment level. Systematic study the influence of different thickness snow covered on the time, rate and growth speed of the grass reviving through continuous dynamic measure the grass growing development, the soil temperature and the soil moisture. Research results show that: The snow has"heat retaining effect"on the pilot soil and the surface soil (0 ~ 30 cm) temperature has little outside influence until the end of grass turning green period when the snow has greater thickness. The surface soil moisture content was gradually decreased per day with the snow melt rapidly and rose to a peak. The curve of soil moisture content was a unit on the shape and the changing time (the peak of 10cm depth snow appeared earlier). The greater thickness of the snow, the bigger influence and the longer effect time of the soil surface moisture content has. During the whole observation period, the average surface soil moisture content was directly proportional to the snow thickness. A certain snow thickness was better for the grass reviving and growth and thicker snow will be result the grass reviving time slightly late, but this does not affect the overall growth of grass. In addition to 30 cm and 40 cm thickness regions, the grass reviving rate has significant difference among these regions with different thickness snow; the grass growth rate shows the trend from fast to slow and the total biomass are on the increase. In the thicker snow regions (such as 40 cm and 50 cm), the growth rate and above-ground biomass during initial reviving period are slower than the regions which snow thickness are 10 cm, 20cm and 30 cm. The growth rate has accelerated noticeably in the reviving medium-term and has equal or surpass to the other plots.
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