A light-conductive board and a rear light module using the light-conductive board is disclosed. The light-conductive plate having a light-emitting face, a light-reflecting face, and at least a light-entering face and the light-reflecting plate adhered onto the external of the light-reflecting face of the light-conductive board, an optical film including a divergent lens and a convergent lens mounted onto the external of light-emitting face of the light-conductive board, a lamp reflector which encloses a lamp source, and the light-entering face of the light-conductive board corresponding to the circumferential edge of the light-entering recessed region of the lamp source adjacent to the light-emitting face or one of the face of the reflection face at least forms into a protruded section.