An image sensing system comprises photoelectric conversion element array which responds to the light from a subject and produces charges responding to the quantity of incident light, storage parts temporarily storing the charges produced by the array and a shift register which receives and outputs the charges in the storage parts. A first gate is installed between the array and the storage parts and a second gate is installed between the storage parts and the shift register. The storage time of the charges and the like can be controlled by controlling the first and the second gates by a control circuit. Then, when the subject is of high luminance, the charges are stored into the storage parts with the array and storage parts connected intact to each other by putting the first gating means in the ON state, and the completion of integration thereof is performed by putting the first gate in the OFF state. Also, when the subject is of low luminance, storage of charges is performed in the array with the first gatge put in the OFF state, and a dark charges produced in the storage parts during that time is discharged before storing the charges of the above-mentioned arrays.