For efficient decision making unit(DMU) on techical efficieny defined by Li Guangjin and Yan Hong, this paper proves that it is DEA efficient ?(C2GS2),? then it is discussed that inefficient DMU is transformed efficient.

• 对李光金、阎洪先生所定义的技术有效的决策单元；证明了它是DEA有效(C~2GS~2)的；而且讨论了将非有效的决策单元转变为有效.