In recent years, the concept of green world, environmental protection and sustainable development has gradually become popular and penetrated into all walks of life. This is no exception for computer systems, and the concept of the green data center is proposed under this background. The meaning of the green data center is to improve the energy efficiency of the data center, minimize the overall power consumption of the data center, maximize the proportion of the IT system in the overall data center power consumption, minimize the power consumption for non-computing equipment (power conversion, cooling, etc.). Green data center has become an important concept and goal of cloud computing technology development. This lecture introduces the relevant technologies of green data center, including virtualization technology, data center scheduling technology, and virtual machine migration technology. This lecture will help you better understand cloud computing and data center management, and current research hotspots.