An encoding apparatus of a video security system in which a stream to be stored in a storage medium and a stream to be transmitted through a network may be simultaneously or separately generated using one encoding chip. The encoding apparatus includes an image encoding unit which encodes an input image, received from a surveillance camera, selectively under at least one of an advanced video coding (AVC) scheme complying with an H.264/AVC standard to generate and store an AVC-encoded image in a storage medium, and a scalable video coding (SVC) scheme complying with the H.264/AVC standard to generate and transmit an SVC-encoded image to a network.