用调幅式ＤＳＣ等新技术研究了物理老化对无规聚苯乙烯多种性能的影响．随着老化时间的延长，试样的玻璃化转变温度、热焓松弛、峰温、峰高和热焓提高；老化使材料的初始模量，屈服应力和断裂强度都有不同程度的提高；使样品的溶剂扩散速率降低，但对样品的密度和声传播速度几乎没有影响．以上这些结果可从物理老化引起试样中凝聚缠结增加的观点来进行解释． The effects of physical aging on the properties of random polystyrene were studied by using the new technology of amplitude modulation DSC. With the extension of aging time, the glass transition temperature, enthalpy relaxation, peak temperature, peak height and enthalpy of the sample increase; the initial modulus, yield stress and fracture strength of the sample all increase to some extent; The sample solvent diffusion rate decreases, but the sample density and acoustic velocity almost no effect. These results can be explained from the point of view that the physical aging causes the increase of cohesion and entanglement in the sample.