Abstract: A method of fabricating a light pipe of an image sensing device including following steps is provided. A substrate is provided. The substrate includes a pixel region and a periphery region. A light sensing region has been formed in the substrate. The light sensing region is located in the pixel region. A dielectric layer is formed on the substrate. An interconnection structure and a light-blocking metal layer have been formed in the dielectric layer. The light-blocking metal layer is located over the interconnection structure, and the light-blocking metal layer has an opening exposing the light sensing region. A portion of the dielectric layer exposed by the opening is removed by using the light-blocking metal layer as a mask to form the light pipe in the dielectric layer.