Deterioration of marine concrete structures and its strengthening are challenges of the world of today. Recently, the increasing use of carbon fiber reinforced polymer (CFRP) composite appears to be a solution for strengthening of the concrete reinforced (RC) structures because of its physical and mechanical properties. This study aims to investigate the shear contribution of CFRP as a composite material in RC beams. In order to achieve this aim three RC beams investigated. One is un-strengthened and remainder two beams were externally shear strengthened in two scheme, U wrap and 2-side wrap with CFRP. Results indicate that CFRP increase the shear strength of the RC beams significantly. Moreover, the findings of this paper confirmed that the shear capacity predicting by design codes is higher and conservative than the experimental results. © 2016 Taylor & Francis Group, London.