Abstract: In this paper, soil humidity values were measured in the Juntang River Basin in northern slope of the Tianshan Mountains in 2009 and 2010 to study the change trend of soil humidity and compare soil humidity in snow melting season. The results show that the change trend of soil humidity was similar at soil depth from 0 cm to 40 cm in the study area, but its difference at soil depths of 20 cm and 30 cm was quite different. Correlation analysis was used to analyze the relationships between the soil humidity and the soil temperature at depth of 0-40 cm, air temperature at 2 m height and snow cover depth. The results reveal that soil humidity at different depths is jointly affected by air temperature, snow cover depth and soil temperature, but the main factor affecting soil humidity is difference from different soil layers. Moreover, the relationship between soil humidity and snow-melting flood peak in 2009 and 2010 was also analyzed, and the results revel that a flood may occur if the change of soil humidity below 20 cm was low, on the contrary, there was no flood if the change of soil humidity was high. The study results can be referred in the further study on developing snow melting runoff models and predicting snowmelting flood.

Key words: snow melting season, soil humidity, snow cover depth, air temperature, soil temperature, snow-melting flood, Juntang River Basin, the Northern Slope of the Tianshan Mountains