The dynamic mechanical properties of oxygen free copper has been tested under the different strain rate（ 2 500s- 1,15 500 s- 1） at the room temperature by split Hopkinson pressure bar（ SHPB）,the true stress-true strain curves has been obtained. Power-Law constitutive model and Johnson-Cook constitutive model have been built to fit the experimental result from SHPB test of oxygen free copper. The results show that the plastic flow stress of oxygen free copper is not sensitive to the strain rate,however,the yield stress increases obviously and the strain strengthening effect decrease when the the strain rate is higher than 14 000 s- 1. In addition,the Power-Law constitutive model can predict the plastic flow stress of the oxygen free copper more accurately than the Johnson-Cook constitutive model at the high strain rate.