Abstract: Temperature and precipitation are mainly impacting factors to soil humidity, and it is important to regional agricultural production, ecological environment improvement and economic sustainable development. Based on temperature and precipitation data at 73 weather stations from 1984 to 2007 in Heilongjiang province, and soil humidity data from 13 soil observational stations, the relationships between soil humidity and temperature, precipitation were analyzed using methods of an EOF and a correlation analysis. The results indicated that soil humidity differs in the different regions of Heilongjiang province from 1984 to 2007. The variation trends of soil humidity are consistent in most agricultural regions except in the middle and west of the Sanjiang plain. Soil is wet before the middle period of 1990s and becomes dry afterwards, while it is seriously dry in 2001. The sensitivity of the soil humidity to climate change differs. Soil humidity is sensitive to temperature in the Songnen plain and to precipitation in the Songnen plain except that in the west and south of the Songnen plain and in the regions of the southern Yichun, the eastern Harbin and the western Sanjiang plain, while it is not sensitive to temperature and precipitation in the regions of Xunke, the northern Yichun, Mudanjing and the eastern Sanjiang plain.

Key words: Soil humidity, Temperature, Precipitation, Sensitivity