Snow cover over the Tibetan Plateau is a sensitive indicator of mean conditions of temperature and precipitation at such high elevation. It is also closely related to the energy and water balance in the eastern and southern Asian regions. However, due to lack of snow observations over the Tibetan Plateau in the past, variability of snow cover over the Tibet area as well as its weather and climate impact have not yet been well investigated. NASA MODIS satellite derived high-resolution snow data have provided very good data sources and opportunities for studying these important problems. In this study, we used MODIS satellite derived snow data over last 7 years to characterize the seasonal variability of snow cover over Tibetan Plateau. The variation of snow cover area, frequency and duration over last 7 years were analyzed. In addition, available Chinese in-situ snow data over Tibetan Plateau were also used for calibration and evaluation purposes. Detailed results will be presented at the conference.