Abstarct: The main objective of this research is to investigate the pull-out behavior of spirally steel fibers and mechanical properties of fiber reinforced composites. The research is divided into three parts. In the first, mechanical properties of cementitious matrix including compressive strength have been determined. In the second part, pull-out behavior of spirally steel fiber has been evaluated by means of experimental tests on single fiber embedded in cementitious matrix. The effect of fiber embedded length and angle of inclination and Matrix compressive strength are evaluated together with the interaction of these parameters. The experimental program involved single fiber pull-out test of five inclination angle and three embedded length. The studied inclination angles were 0, 15, 30, 45 and 60 degrees. The embedded lengths were 10, 15 and 20 mm. Compressive strength of matrix was 20 and 30 Mpa. The length and diameter of spirally steel fibers were 40 mm and 0.4 mm, respectively and their tensile strength was 1500 Mpa. The pull-out results indicated that the spirally steel fiber exhibits slip-hardening behavior as aresult of plastic hinge formation in spirally part of fiber. This mechanism increases bond strength and pull-out energy of fiber. In the final part, In order to evaluate the tensile behavior of cementitious composite baxse materials reinforced with helical fibers, the tensile behavior of fibrous concrete has been investigated by performing direct tensile test on dumbbell-shaped samples. In this section, the behavior of fiber reinforced concrete is evaluated by examining the relevant parameters such as bearing capacity, energy absorption and post-cracking behavior. In order to compare different tensile behavior of composites, Direct traction tests performed on cementitious composites reinforced with 0.15% and 0.25% spirally steel fibers with Compressive strength 25 Mpa. The result showed that cementitious composites with 0.15% and 0.25% spirally steel fibers exhibit defection-softening behavior. The percentage of fibers in the matrix plays an important role in increasing the strength and energy absorption after cracking.