Corrosion of steel tube members used for road appendages has been confirmed. CFRP bonding repair and reinforcement of steel tube members are effective for preventive maintenance. However, few studies have evaluated the debonding of CFRP ends. In this study, four-point bending tests were conducted on CFRPbonded steel tubes. Debonding of CFRP ends occurs on the side subjected to tension due to bending moments. Experimental results were compared using shearlag theory. Within the elastic range, the strain distributions of the shear-lag theory and the experimental results generally agreed with each other.