An image sensor package includes a substrate, a sensor chip, a light-permeable cover, and a particle blocking dam. The substrate has a chip accommodating space, and the sensor chip is disposed in the chip accommodating space and electrically connected to the substrate. The light-permeable cover is disposed on the substrate and disposed above the sensor chip. The particle blocking dam is disposed above the sensor chip and extends from the light-permeable cover toward the sensor chip so as to be in contact with or close to the sensor chip.