A sensing device includes a substrate, two chips, and a shielding structure. The two chips are respectively defined as an emitting chip and a receiving chip. The emitting chip can emit a sensing light beam, the receiving chip can receive the sensing light beam, and the two chips are fixed in position on the substrate at intervals. At least one of the chips is electrically connected to the substrate through at least one wire, and a position where the wire is connected to the substrate is located between the two chips. The shielding structure is formed on the substrate. The shielding structure is located between the two chips, and the shielding structure covers the wire and a portion of the chip connected to the wire. Compared with the conventional photo-plethysmography sensor, the sensing device has the advantage of a smaller size.