A data storage medium in which multiple bitstreams are recorded, an apparatus and method for recording the multiple bitstreams, and an apparatus and method for reproducing the multiple bitstreams are provided. The reproducing apparatus includes: a reading unit for reading main data including audio data and/or video data, and reading sub data recorded in a separate bitstream from the main data, which is later reproduced in synchronization with the main data; and a multiplexer for multiplexing the main data and sub data read by the reading unit. Therefore, multiple bitstreams can be read and reproduced at the same time.