Traffic safety problem becomes increasingly serious as a result of the rapid development of China automobile industry as well as increasing car’s ownership. The occupant road traffic injury data of NASS / CDS database (2005-2010) are systematically explored to statistically analyze injury characteristics and effects of collision velocity and angle for those occupants with lower extremity injury in frontal crash. Results of the present study has significant value on the design of vehicle crashworthiness and occupant restraint system.