Abstract: In order to understand the mechanical properties of concrete at different ages under dynamic loads systematically, the impact compression tests of 5 early aged concrete were conducted with a 75mm diameter split Hopkinson pressure bar (SHPB). And static compression tests, for comparison, were also conducted with an INSTRON system. The experimental results show that, although the growth model of concrete strength and elastic modulus under static load are different, both of them increase with the growth of the age, while critical strain decreases with the growth of the age in general; under dynamic loads, the concrete compression strength, critical strain and unit volume absorbed energy increase with the growth of the age, all of them are sensitive to strain rate and the growth trend of concrete dynamic strength with strain rate can be presented with an index function. Under dynamic loads, the concrete is destroyed in a tensile failure mode. And a shear failure mode was presented for concrete under static loads.