Accurately understanding the characteristics of land use / cover change (LUCC) in Tibet Autonomous Region and exploring its driving factors are of great significance to scientifically predict the trend of land use change in Tibet and make economical and intensive use of land resources. Based on the five periods of LUCC data from 2000 to 2020, this paper analyzed the characteristics of LUCC in Tibet Autonomous Region from dynamics and transformation trend. The results showed that: (1) LUCC in the study area was mainly grassland, forest land and unused land. The change frequency was the highest from 2015 to 2020, and the change areas of urban and rural construction land, cultivated land and water area were relatively concentrated in space. (2) Urban and rural construction land continued to grow, grassland continued to shrink, and other land types increased in a fluctuating manner. (3) LUCC in the "One River and Three Streams" Basin of Tibet were rich in species and complex in causes. The rest of the areas were dominated by grassland and unused land changes. (4) Over the past 20 years, there have been many driving factors for LUCC in Tibet. Natural factors played a decisive role in the distribution of cultivated land and water areas, while socio-economic and policy factors had a great impact on LUCC in Tibet in recent years. The transformation of land use types was complex, and there were significant differences in the change characteristics of different types, among which the biggest change was the transformation between grassland and unused land. The driving factors of LUCC in Tibet were complex. Climate change and human activities had a significant driving effect on land use changes in the study area.