As a paradigm for sustainability, green growth is commonly regarded as an approach to breaking away from economic stagnation and therefore receives widespread attention by theorists and supranational institutions. However, it is still a new concept and lacks of a consensus on its definition. By tracing the background of green growth, this paper combs various definitions in different points of view, summarizes its implementation path under different conditions, concludes that policy, technology and investment are the three key drives of green growth and presents a mechanism of action.