This paper describes the deformation behavior and the bond characteristics of the RC beam with all lapped splices at the critical region. The lapped splices are that main bars were put on top of another. Main contents of investigation are the effect of spliced arrangement on deformation behavior, the relationship between bond splitting strength and ratio of transverse reinforcement. At spliced specimens, bending clack concentrated on the lapped splices edge, but bending deflection was independent of spliced arrangement, 80% of the whole as non-spliced member. The bond splitting strength was evaluated by assuming the truss mechanism.