Abstract:Vegetation coverage is an important physiological parameter for describing the growing status of vegetation, and plays a key role in some ecological processes such as evapotranspiration, soil erosion, and photosynthesis etc. So vegetation coverage is considered to be an important indicator of ecosystem change. In this paper, the temperate steppe of Inner Mongolia was chose as study area, and following two questions were brought forward and expected to be solved: (a) how were the changes in vegetation coverage happened temporally and spatially? (b) What kinds of relationships exist between vegetation coverage changes and some climatic factors, including air temperature and precipitation? In order to understand these two questions, the NDVI product images of NOAA/AVHRR were used to calculate vegetation coverage in temperate steppe of Inner Mongolia from 1982 to 1999, and then correlation coefficients between vegetation coverage and climate factors were calculated. Climatic factors were combined into different patterns based on the observed time periods and time lags for finding out the temporal responses of vegetation coverage to climate fluctuation or change. The main findings were as follows: (a) Increasing trend of vegetation coverage in whole study area is clearly during last 18 years. The vegetation coverage in 72% of total area has been increased during last 18 years, and the most obvious increase was occurred in the typical steppe areas among three types of steppe; (b) The average vegetation coverage of growing season and monthly vegetation coverage have positive correlation with precipitation, and negative correlation with temperature. The impacts of precipitation on vegetation coverage show in time-delay and cumulative effects. (c) The sensitivities of vegetation coverage to climate factors were different among three kinds of steppes, and vegetation coverage was most strongly related to climate factors in desert steppe.