A water ring scanning apparatus and method, and an apparatus and method for encoding/decoding video sequences using the same are disclosed. A water ring scanning apparatus includes: a preferential scan unit for scanning information on a water ring origin point (water_ring(0)) in an image frame, which is a most significant bit of the image frame to be preferentially scanned; a scan location decision unit for deciding a location of i_th generated water ring (water_ring(i)), which is a rectangular-shape ring surrounding the water ring origin point; and a scan unit for scanning information on the location of the i_th generated water ring.