We focus here on the Energy Efficiency (EE), and propose an improved dynamic clustering algorithm that is incorporated into Coordinated MultiPoint (CoMP) with sleeping mode. Thanks to the frame structure of Benefit-tree employed in dynamic clustering of CoMP, the proposed algorithm can significantly improve the EE by choosing the most energy efficient competitive clustering strategy. At the same time, it can save energy by sleeping the underutilized base stations in the cellular network. In the performance simulation for EE, the proposed algorithm provides 10% higher in EE than the existing algorithm,