This paper presents the mechanical behaviors of hybrid fiber reinforced plastic (HFRP) composite beams. There are two methods were proposed to increase the stiffness of pultruded glass fiber reinforced plastic (GFRP) beam and change the failure mode. The first method is to infill the epoxy mortar into the GFRP beam. The second method is hand layout the GFRP beam by using carbon fiber with different direction fibers to increase the stiffness of the GFRP beam. Three-point bending test was conducted to obtain the force-displacement relationship, stiffness, failure strength and failure mode of the GFRP beams. The test results show that the stiffness of GFRP beam filled with epoxy mortar is twice larger than GFRP beam.