Abstract: Using the technology of split Hopkinson bar,the dynamic mechanical behavior of four kinds of typical microstructure of TC6 titanium alloy under the condition of high strain-rate loading have been studied and the effects of original microstructure on the dynamic mechanical behavior have been analyzed.It is showed that the stress of the four typical microstructure of TC6 titanium alloy displayed the same variation rule under the condition of high strain-rate loading.At the beginning of deformation,strain is less and stress is quickly increased.The subsequent stress vibrates with increase of the strain.When reached the peak,the flow stress gradually decreases with the increase of the strain and displays a steady-state flow.The final stage of deformation,the flow stress fast fall down.The flow stresses of the four kinds of microstructure of TC6 titanium alloy display the ascending tendency with the increase of the strain-rate under the condition of high strain-rate of 103s-1 order.All of four kinds of microstructure of TC6 titanium alloy are sensitive materials to the strain-rate,but their strain-rate effects are different.The TC6 alloy with lamellar microstructure displays higher sensibility to the strain-rate,whereas the TC6 alloy with the solution and aging microstructure displays lower sensibility to the strain-rate.The sensibility of the equiaxed microstructure to the strain-rate is similar to that of the binary microstructure.