The influence of mix quantity of polypropylene fiber to the key property of concrete was studied based on the mechanical experiment of polypropylene fiber concrete. The test result indicated that both the compressive strength and the splitting tensile strength of polypropylene fiber concrete were reduced with the increase of the mix quantity of the fiber. When the mix quantity increased from 0 to 1.2 kg/m3, the 7 d resistant to compression and the tensile strength of the fiber concrete reduced by 11.4% and the 8.7% respectively comparing with those of the control concrete, the 28 d intensity of the fiber concrete reduced by 12.1% and 3.6% separately,but the anti-impact ability of concrete enhanced by 4.76 times. Moreover, the addition of the polypropylene fiber enabled a higher toughness of concrete, which is crucial to the prevention of deformation and cracks of normal concrete under loads.