In this study, high-speed tensile testing for notched specimen is conducted to investigate the impact property of Polydimethylsiloxane copolymerized Polycarbonate (PDMS-PC) compared with Polycarbonate (PC). Depending on the test temperature and tensile speed, brittle or ductile fractures are observed for PC. However, only ductile fractures are seen for PDMS-PC even at the high speed 7000mmis and low temperature 243K. The impact properties are also considered in terms of the time-temperature superposition principle. Then, master curves for the final fracture elongation for both PC and PDMS-PC are constructed in terms of the strain rate at the notch in conjunction with shift factors.