An image sensor includes a storage block for storing a plurality of pixel data which is transmitted from a pixel array block; a switching block for delivering a first pixel data from the storage block in response to a first control signal; a defect pixel repairing block which is controlled by the first to fifth control signals PASS, DPCA, MS, ISCA and Line End in order to receive surrounding pixel data having the first pixel data from the storage block and the first pixel data from the switching block and output a revised pixel data by using the first pixel data or the surrounding pixel data; and a image signal handling block for receiving the first pixel data outputted from the switching block or the revised pixel data outputted from the defect pixel repairing block and operating an image process in order to improvement of the image sensor.