A moving picture data recording/reproducing system. In recording operation, moving picture data of a first frame row including frames selected from frames of an input picture signal for every predetermined number of frames are coded in accordance with an intra-frame coding method in which coding is completed within each frame, while picture data of a second frame row including the other frames are coded by an inter-frame coding method assuring a high compression ratio. The coded data resulting from the inter-frame coding and the intra-frame coding are multiplexed by interleaving them in the order of the frame numbers, the multiplexed data being then recorded on a recording medium. In reproducing operation, the multiplexed data are read out for reproducing the moving picture signal or alternatively the intra-frame coded data of the first frame row are selectively read out for reproducing the moving picture signal.