This invention relates to a packaging structure and method of an image sensor module. The method comprises: providing a transparent substrate having a first patterned conductive layer; carrying an image sensor integrated circuit chip having a photosensitive active area and at least one passive chip on the transparent substrate, wherein the photosensitive active area faces the transparent substrate; forming an insulating build-up film over the transparent substrate; and forming a plurality of conductive vias in the insulating build-up film wherein the ends of the conductive vias are connected with the passive chip or the first patterned conductive layer of the transparent substrate while the other ends of the conductive vias are exposed on the surface of the insulating build-up film. The packaging method is capable of down-sizing the construction of the image sensor module and simplifying the processing steps.