The physical aging behavior of atactic polystyrene (aPS) films achievedunder different drawing conditions has been studied by optical birefringence and modulatedifferential scanning calorimeter (m.d.s.c.). The results show that on annealing at specifictemperature below glass transition temperatue (Tg)

the enthalpy relaxation (△H) and Tg decrease with increasing of birefringence (△n). On the other hand

the effect of moleculardraw ratio (MDR) is confusing: △H and Tg decrease with increasing of MDR in the early stage of aging

but the MDR's effect become unobvious with the development of aging. It may be concluded that the ordered domain generated by the drawing below or above glass transition temperature will affect the development of physical aging behavior.The viewpoint of cohesional entanglement is used to account for the above observations.