Abstract: In order to study the flexural impact behavior of Crumb Rubber Concrete(CRC) beams,Coarse crumb rubber and fine crumb rubber is used to prepare CRC,and three kinds of interfacial modifiers(X,Y,KH550) are chosen to modify CRC.The test results show that the initial-crack,fracture impact cycle number of concrete are improved by incorporating of coarse rubber,and are decreased by incorporating of fine rubber.The flexural impact behavior of CRC modified by interfacial modifiers increases significantly.