Due to the rapidly growing demand for mobile communication technology, the number of worldwide cellular BSs has increased from a few hundred thousand to many millions within a last couple of years. Energy efficiency in cellular networks is a growing concern for cellular operators to not only maintain profitability, but also to reduce the overall environment effects. Base stations consume a maximum portion of the total energy used in a cellular system. In general switching off base stations (BSs) is an effective and efficient energy-saving solution for green cellular network. However, this approach incurs such problems as service disconnection and quality degradation to users who are connected to previously switched-on BSs. There are no previous work jointly considering power control and BS cooperation. In this project, the proposed system study the problem of QoS-aware green cellular networks by using BS cooperation to en-large coverage for scenarios with different user distributions and BS power models. The objective is to ensure the user demands are satisfied while achieving minimal system power consumption. Also the system decide which set of BSs to cooperate and which set of BSs to switch off. It observe that a higher cooperative size does not imply a better strategy for different scenarios. Furthermore, we propose two heuristic algorithms accounting for the properties of energy savings and the constraints of bandwidth resources. The result shows that the algorithms outperform the pure power control scheme and the pure cooperation without power control mechanism and consume less power under any traffic loads. Simulation result demonstrates that the proposed mechanisms are efficient in energy consumption in low-load and high-load traffic.