This paper presents a study of the tensile fracture properties of Ultra High Performance Fiber Reinforced Concrete (UHPFRC) considering the effects of the fiber content. To investigate the impact of fiber content, notched 3-point bending tests were executed, where the fiber volume ratio was varied from 0% to 5%. From the bending tests, it was found that the flexural tensile strength of UHPFRC linearly increases with increasing fiber volume ratio and the rule of mixture can be applied to UHPFRC. Furthermore, an inverse analysis was performed to determine the tensile fracture model of UHPFRC and a tri-linear tensile softening model is suggested. The suggested model successfully represents the increase of the stress-constant bridging zone and the decrease of the stress-resisting zone with increasing fiber content. The proposed model for various fiber content levels is simple and versatile and can be readily applied to structural design or numerical analysis of UHPFRC. (C) 2009 Elsevier Ltd. All rights reserved.