An encoding apparatus and method for encoding supplementary information of a three-dimensional (3D) video may determine that an updated parameter among parameters included in camera information and parameters included in depth range information is a parameter to be encoded. The encoding apparatus may generate update information including information about the updated parameter and information about a parameter not updated, perform floating-point conversion of the updated parameter, and encode the update information and the floating-point converted parameter. A decoding apparatus and method for decoding supplementary information of a 3D video may receive and decode encoded supplementary information by determining whether the encoded supplementary information includes update information. When update information is included, the decoding apparatus may classifying the decoded supplementary information, perform floating-point inverse conversion of the updated parameter, and store latest supplementary information in a storage.