This paper describes the retrofitting behaviors of concrete specimens strengthened by carbon fiber reinforced plastics (CFRP).The specimens in this study are divided into three categories and they are spiral/tied concrete cylinder, pure concrete beam and reinforced concrete beam, respectively.Parameters under consideration include the strength of concrete, spacing of spiral/tied reinforcement, fire-damaged level, and CFRP retrofitting.All the concrete specimens were extemally strengthened by CFRP and then loaded by the loading test.The strength and ductility of concrete specimens strengthened by spiral/tied reinforcement and CFRP were evaluated.