Abstract: Dynamic compression experiments on a special steel were carried out using a common SHPB system and a two-specimen SHPB system. The dynamic compression stress-strain curves were obtained for different strain rate history. The effect of strain rate history on the stress-strain curves was investigated through comparing the two stress-strain curves with the same average strain rate but different strain rate history for the same specimen. The results show that the stress-strain curves are significantly affected by the strain rate history, and this effect must be accounted for in the study of material constitutive relations.