A flexible substrate includes a circuit board, a flexible heat-dissipating structure and an adhesive. The circuit board has a substrate and a circuit layer formed on a top surface of the substrate, and the flexible heat-dissipating structure has a flexible supporting plate and a flexible heat-dissipating metal layer formed on a surface of the flexible supporting plate. The flexible heat-dissipating metal layer of the flexible heat-dissipating structure is connected with a bottom surface of the substrate by the adhesive. The circuit layer and the flexible heat-dissipating metal layer are made of same material.