Abstract: PEG as phase change materials, which is close to body temperature in the use of temperature range, and which is the basis of textile material. Differential scanning calorimetry (DSC) was used to test and analyze the different molecular weight PEG and two components PEG system, in order to measure their phase change behavior and characteristics and investigate the influence of the different mass ratio PEG1000/ PEG2000 system on the phase change behavior. The result showed that molecular weight and proportion of PEG had effect on phase change energy and temperature change, and the PEG1000/ PEG 2000 system was more suitable as an energy storage material for temperature auto-control textile; also the molecular weight of PEG had effect on two components PEG system, there was bimodal phenomenon in the heating direction; phase change behavior was accurately changed by adjusting proportion of two components system.