The 3GPP long term evolution (LTE) standard is developed to enhance mobile services from the former 3G systems. In order to prolong the battery life of mobile device, a novel discontinuous reception (DRX) scheme is specified in the standard to reduce the power consumption of a user equipment. In this paper, a traffic-based DRX cycles adjustment (TDCA) scheme is proposed to enhance the energy saving performance based on existing DRX operation. A partially observable Markov decision process (POMDP) is employed to conjecture the present traffic status. Optimal policy for the selection of DRX parameters can be obtained via the POMDP framework in the proposed TDCA scheme. Simulation results show that the TDCA scheme can enhance the energy saving efficiency while the quality-of-service constraint is still satisfied.