An optical disk for recording stereoscopic videos and high-quality video signals and a system for reproducing the videos and signals from the optical disk are made compatible with the conventional video reproducing system. A reproducing device which is used for reproducing stereoscopic videos and high-quality videos obtains stereoscopic video or high-quality videos by reproducing both first and second interleaved blocks on the optical disk in which first and second video signals are alternately recorded on the left and right sides by dividing the first and second video signals into frame groups of one GOP or more and a reproducing device which is not used for reproducing the stereoscopic videos and high-quality videos obtains ordinary videos by only reproducing either the first or second interleaved block by jumping tracks.