In recent years, the world has embraced rapid and large-scale urbanization making more citizens share the progress of society, such as abundant commodities, convenient and fast transportation, excellent medicine and education. For the urbanization, more land inside or around the limited cities have been exploited at the expense of greenery to build buildings as well as infrastructure to satisfy the according demands caused by urbanization. But human beings can never live without greenery, and more citizens mean more needs on greenery. In view of this, the importance of greenery has been increasingly recognized by urban planners and policy makers. This essay aimed to explore the role that greenery plays in urban planning in modern Britain and provided the theoretical basis for better utilization of greenery in the future urban planning.