A signature management apparatus and method of cutting-out streaming data. The signature management apparatus includes a signature-related information preparing device which prepares signature-related information for streaming data, a signature-related information storage device which partitions a sequence header of the streaming data into stream header information needed for reproduction of the streaming data and user header information which a user can freely use for storage, and stores the signature-related information within the user header information in a form that allows no start code to emerge.