Abstract: In order to use energy effectively, energy efficiency (EE) has been one of the main topics of green wireless communication research. To improve the energy efficiency of multi-antenna system, a generalized spatial modulation system based on energy efficiency optimization was proposed, named as EE-GSM. The proposed system was based on maximizing energy efficiency criteria, considered the case of large number of transmit antennas, and can be implemented by two steps. Firstly, transmit antenna selection algorithm was used to decide the optimal transmit antennas subsets. Then, the selected transmit antennas subsets were used to calculate the most appropriate radio frequency chain (RFC) number for the generalized spatial modulation system. The simulation results and analysis demonstrate that the proposed scheme compared with the traditional AS-MIMO (antenna selection-multi-input and multi-output) system, GSM system and SM system not only can effectively improve overall system energy efficiency, but also can improve BER and sum-rate capacity performance of GSM system, while the final desired number of RF channels of the system is generally 2,3 or 4, which is consistent with the principles of green wireless communication.