Seasonal variations of snow cover fraction (SFC) over the Tibet Plateau (TP) are examined using the data acquired from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra spacecraft. In this study, we first evaluate the accuracy of the MODIS high-resolution snow cover data by comparing the data with in-situ Chinese snow observations. Results show that overall accuracy of MODIS snow data is about 90% over the TP area. Statistical analysis is then performed over the MODIS snow data during 2000--2006. It is found that the most persistent snow cover is located in the southern and western edges of the TP within large mountain ridges and western part of Yarlung Zangbo valley. The higher SCFs are mostly concentrated in the regions where the elevation is higher than 6000 m. The duration for snow persistence varies in different elevation ranges and generally becomes longer with increases in the terrain elevation.