The development of smart cities is inseparable from the application of edge computing technology. The value of edge computing in smart cities is reflected in specific application scenarios. So, this chapter mainly introduces the definition of smart cities and their architecture, and enumerates some applications with edge computing technology. It also introduces how edge computing technology is applied in dealing with urban traffic congestion. Next, the computation offloading, resource allocation and task scheduling problems in edge computing -enabled smart city are discussed according to the academic research. Finally, we discuss the security and privacy problem in edge computing -based smart city. The application of edge computing in smart cities is much more than that mentioned in this chapter. With experts and scholars in different domain investing in edge computing research, the role of edge computing in smart cities will be further enhanced.