A method of fabricating a high-sensitivity image sensor and the same are disclosed. The disclosed method comprises: etching predetermined regions of active silicon and a buried oxide layer of a SOI substrate by using a mask to expose an N-type silicon substrate; implanting P-type ions into the exposed N-type silicon substrate to form P-type regions; forming a gate oxide layer and a gate electrode on the middle part of the active silicon not etched while the active silicon is etched to expose the N-type silicon substrate; forming a P-type gate electrode, and P-type source and drain regions by implanting P-type ions into the active silicon and the gate electrode above the buried oxide layer; and constructing a connection part to connect the P-type regions to the gate electrode. The disclosed high-sensitivity sensor comprises: a photodiode region having a PN junction between an N-type silicon substrate and a P-type region thereon; a monocrystalline silicon region from a SOI substrate in which source and drain regions, and a channel are placed, having a distance to the photodiode region; a gate oxide layer and a gate electrode on the silicon region; and a connection part connecting the P-type region of the photodiode to the gate electrode.