A light source package structure is provided. The light source package structure includes a substrate, an upper electrode layer, a light emitting unit, a photodiode, a surrounding wall, a light permeable element, and a coating layer. The substrate includes a first surface and a second surface that is opposite to the first surface. The upper electrode layer is disposed on the first surface of the substrate. The light emitting unit and the photodiode both are disposed on the upper electrode layer. The surrounding wall is disposed on the first surface and is arranged to surround the light emitting unit and the photodiode. The light permeable element is disposed on the surrounding wall. The coating layer is disposed inside of the surrounding wall and is coated on a part of the first surface and a part of the upper electrode layer.