AbstractPolydicyclopentadiene (PDCPD) was prepared in a simulating reaction injection molding system. Dry friction behaviors of the PDCPD under elevated sliding velocity (5m/s, 10m/s, 15m/s, and 20m/s) against GCr15steel were investigated on a high-speed pin-on-disc tribometer. Their microstructure changes on sliding surface were examined by using scanning electron microscopy (SEM). The results showed that the wear mass loss of PDCPD increased with the increase of sliding velocities. The friction coefficients of PDCPD under a sliding velocity of 5m/s were the most stable, and the friction coefficients were irregular with the further increasing the velocity. The results of SEM analysis showed that the wear mode is typical abrasive wear at a sliding velocity of 5m/s and the wear mode had transformed into typical adhesive wear at a velocity of 20m/s.