The creep characteristics of polycarbonate at elevated temperatures are investigated. The onset of glass transition temperature of polycarbonate is determined. An Arrhenius type relationship is used to describe the creep process and the concept of property retention index as applied to creep is discussed. An attempt is made to construct the master rupture curves for polycarbonate. The onset of glass transition temperature of polycarbonate was placed at around 110-degrees-C. It is concluded that the Arrhenius theory and the concept of property retention index are extremely useful in the construction of master rupture curves and that they require further investigation.