A supporting base for a semiconductor chip comprises a substrate, a surrounding wall and a reflection plate. The surrounding wall is formed on the substrate, and an accommodating space is formed between the surrounding wall and the substrate and is provided for receiving the semiconductor chip therein. The semiconductor chip is electrically connected to the substrate. The surrounding wall includes a cut-out portion on one side thereof. The reflection plate is extend to be bent from the substrate, and the reflection plate is configured to correspond to the cut-out portion and the semiconductor and is formed of an obtuse angle with the substrate. Therefore, with such structure, the present invention is able to achieve the effect of an increased illumination range.