A dummy memory board includes a substrate, a connecting finger, a plurality of light emitting diodes, and an electrical circuit. The substrate has a front surface and a back surface, and is provided with at least one dummy memory region. The connecting finger is close to a lower edge of the substrate for inserting into a memory slot. The light emitting diodes are on the substrate and close to the upper edge of the front surface and the back surface. The electrical circuit is on the substrate for connecting the light emitting diodes to the connecting finger. Thus, power from the memory slot is transferred to the light emitting diodes through the connecting finger, and the light emitting diodes are turned on to demonstrate the desired light effect. Particularly, the electrical circuit has no suspending node or open spot and interference due to antenna effect is avoided.