Recently, M2M (Machine-to-machine) communications are gaining more prominence in wireless communication. However, there are so many differences betwteen human-to-human communications and M2M. This paper focuses on solutions to provid longer battery life time. To save battery power, we studied the discontinuous reception DRX mechanism of M2M devices and proposed a novel self-adaptive DRX mechanism based on mix normal and extended DRX cycles mechanism. The proposed mechanism is a trad-off between power consumption and latency acording to different QoS requirements. The simulation shows the advantages of this new solution for M2M UE power saving.