Researches in the development of building materials which are some of the mostvital requirements for the survival of human beings are always on the rise day by day. Concrete, being one of the most reliable and widely used materials is in the construction industry, is the main focus of this research. The use of fibers to improve different properties of concrete has already been a known method for several decadesnow.In order to achieve improved overall performance of a structure we need tounderstand the type and nature of load transfer within the whole structure, and be able to point out the main load bearing structural members.Improving the properties ofany given member will eventually have a significant effect on the whole structural performance.Each and every member of a building structure takes a specific role inload bearing in one way or another; in this research, the beam, as one of the main loadbeating members in most of concrete structures, is the center of focus. It is generally known that a beam in a structure is in mainly subjected to bendingloads. This paper is therefore mainly focused on the bending performance of beams inconcrete structures. Several concrete beams were prepared and reinforced with one ortwo types of fibers in order to research on the effect of different types of fibers ontheir bending performance. 　　Flexural toughness tests are performed to investigate the influence of hybrid fibers on the toughness of Reactive Powder Concrete(RPC).The experiment uses different amounts of high strength steel fibers and macro-polyolefin or micro-polyvinyl alcohol(PVA) fiber.Two kinds of RPC, silica fume and ultra-fine cement RPCs, are prepared to compare their toughness performance.Steel fiber volume fraction is 1％ and 2％ while synthetic fiber contents are 6, 9 and 11kg/m3. From the results of the experiment, the effect of hybrid fiber reinforcement technique on the toughness performance of the two kinds of RPC was discussed.It was observed from the load-deflection curves that strain hardening characteristics of hybrid fiber RPC were achieved, and the general post-peak behavior of the hybrid fiber reinforced specimens at was improved significantly.Hybrid fiber reinforcement method shows significant improvement in the energy dissipation capacity of the specimens, which is a clear indication of improved flexural performance. Comparing specimens with only 1％ steel fibers and those with hybrid fiber, the toughness index T(7) of silica fume specimens increased by 47.3％-98.8％, whereas T(7) of ultra-fine cement RPC specimens increased by 82.3％-215.6％ respectively.For higher volume of steel fiber it is advised to use less amount of micro-PVA fiber. From the general analysis of the bonding properties between RPC and high strength fibers, it is also noted that the excellent properties of both materials are effectively utilized.The nature of failure of fiber reinforced RPC specimens is greatly improved and characterized by appearance of multiple secondary cracks around the main crack, even at the end of the test the specimens do not split into two. The bonding performance of RPC is highly superior to that of conventional concrete, the main reason being due to its excellent uniformity of the aggregates, high compactness, which makes the matrix bind tightly with the fibers or any other reinforcement.