An image sensing device includes a pixel array configured to include a first pixel belonging to a first row and a first column, and a second pixel belonging to a second row adjacent to the first row and a second column adjacent to the first column; and a dual conversion gain (DCG) capacitor coupled between the first pixel and the second pixel, and a first DCG transistor for selectively connecting the DCG capacitor to or disconnecting the DCG capacitor from a first floating diffusion region of the first pixel; and the second pixel includes a second floating diffusion region and a second DCG transistor for selectively connecting the DCG capacitor to or disconnecting the DCG capacitor from a second floating diffusion region of the second pixel.