Abstract: Mechanical properties of steel fiber hybrid polyvinyl alcohol fiber reinforced strain hardening cementitious composites (SF-PVA/SHCC) have been one of the hot topics in recent years. However, there is still a lack of the theoretical model that can fully describe the constitutive relationship of SF-PVA/SHCC in tension. Based on the theory of fracture mechanics and micromechanics of concrete, a new uniaxial tension constitutive model for SF-PVA/SHCC was proposed by considering the softening stage of stress-strain curve and the effect of SF-PVA hybrid fibers on the tensile properties of SHCC. In order to verify the effectiveness of the proposed model, a series of single-axial tensile tests for SF-PVA/SHCC were performed. The influence of fiber type and fiber content on the tensile strength, tensile strain and tensile toughness of SHCC was analyzed. Through the comparison with the experimental results, it was found that the proposed model could well predict the tensile stress-strain relationship of SF-PVA/SHCC composite.