A single gate pixel of an image sensor, architecture of the single gate pixel, and an operation method of the single gate pixel may be provided. The single gate pixel includes a first transfer unit to transfer a charge, generated by a light detector element, to an accumulation (ACC) node, a second transfer unit to transfer the charge, accumulated in the ACC node, to a Floating Diffusion (FD) node, a connection unit to connect the light detector element to a driving voltage, and a reset unit to reset a voltage of the FD node based on a reset control signal.