In order to study the flexural behaviour of steel reinforced engineered cementitious composite (ECC)-concrete composite beams strengthened by carbon fiber sheet (CFS). Totally 12 ECC-concrete composite beam specimens with three types of ECC height replacement ratios strengthened by different layers of sheet and anchorage method (with and without CFS hoops) were made and their static flexural performance tests were conducted. The effect of layers of CFS, ECC height replacement ratio and anchorage method on the bearing capacity, deflection, crack and failure mode of strengthened ECC-concrete composite beams were investigated. The test results show that compared with the unstrengthen beams, the crack width of strengthened ECC-concrete composite beam and the bearing capacity increased by 63% with the increase in the number of reinforced layers. The ultimate bearing capacity of the beams strengthened with CFS hoops increased by 8.6% when compared with that of counterpart without CFS hoops.