The present invention relates to method and apparatus of providing data stream together with program specific information (PSI) requisite for data stream selecting, separating, and decoding of a digital TV set. The present invention, when transmitting PSI to a digital TV set, measures time length of the PSI, creates time information preceding a transport time of the first TP belonging to data stream by the measured time length, converts PSI to at least one TP the created time information is added to, and transmits the converted PSI TPs before data stream TPs. Owing to the PSI provided along with a digital data stream, the digital data stream from a recording medium can be selected, separated, and decoded at a digital TV set without data loss. Furthermore, even though PSI is additionally provided, continuity among time information written successive TPs of PSI and data stream is always ensured.