A supporting structure is provided for a bike-carrying rack which includes a main body. The supporting structure includes a supporting member having a pivot portion pivoted to the main body, and a position-restricting assembly. The pivot portion has an axis, and the supporting member pivotally swings about the axis to be in a carrying position or a folded position. The position-restricting assembly has two restricting members assembled on the main body, the two restricting members are located by two opposite sides of the pivot portion, and a connection direction of the two restricting members is oblique to the axis. When being in the carrying position, the supporting member abuts against the two restricting members; and when being in the folded position, the supporting member at least non-abuts against one of the two restricting members. A bike-carrying rack including the supporting structure is further provided.