The interface between steel fiber and cement matrix could reduce the reinforced effect of fiber in fiber mortar.Two different reinforced methods are introduced to intensify the interface so as to improve the microstructure and mechanical performance of fiber mortar,and these two methods are named silica fume(SF) reinforced and styrene-butadiene latex(SBL) reinforced.The compressive and flexural strengths of mortar aged at 3,28,90 d are tested.The stress characteristics of the steel fiber are studied by mean of theory calculation,and the rupture characteristics of steel fiber and matrix are studied by mean of SEM image.Based on those studies,the conception of rigidity reinforced and flexible reinforced of the interface is proposed.SF is attributing to rigidity reinforced of the interface,while SBL is attributing to flexible reinforced of the interface.In the method of rigidity-reinforced of the interface,fiber bridge effect decreases,leading to the decrease of reinforced effect,while in the method of flexible reinforced of the interface,it does not have such problem.The diversity of different reinforced methods on the long-term mechanical performance is gained essentially.