To observe the dynamic mechanical response and investigate the processes of high speed stamping for C5191 phosphorus bronze, tensile properties and deformation behaviour of C5191 phosphor bronze under quasi-static tensile condition at a strain rate of 0.001 s_-1 by electronic universal testing machine, and dynamic tensile condition at strain rate of 500, 1000 and 1500 s_-1 by split Hopkinson tensile bar (SHTB) apparatus were studied. The effects of strain rate and the mechanism were investigated by means of SEM and TEM. The results showed that the yield strength and tensile strength of C5191 phosphor bronze under high strain rates deformation increased by 32.77% and 32.77% respectively compared with quasi-static condition, the strain hardeningSindexSincreases from 0.075 toS0.251, andSthe strength of the materialSstrain rateSsensitivity indexSchange from 0.005 toS0.022, which presented a clear sensitive to strain rates. The deformation resistance increased with increasing the strain rate due to the stronger short range resistance induced by the acceleration of dislocation motion. The ability of plastic deformation of C5191 phosphor bronze increased due to the number of movable dislocations increased significantly, started multi-line slip, and the soft effect of adiabatic temperature rise at the strain rate ranging from 500 to 1500 s_-1.