The detail exploration of non-structure hydrocarbon reservoirs in Miocene progradational delta in Block J of South Sumatra Basin is restricted by the unclear understanding of the superimposition patterns and spatial evolution law of sandbodies. Based on the analysis of the high-resolution sequence stratigraphy，regional geological setting，lithofacies，logging response，and seismic features，the genetic unit types of progradational delta are identified. A depositional model reflecting the sandstone architectures of progradational delta is established according to their spatial distribution. The genetic-architecture sandbody classification and reservoir prediction methods restricted by the sandbody superimposition patterns are further proposed. The results show that five genetic unit types are identified in study area，including underwater distributary channel，mouth bar，sheet sand，distributary inter-channel and pre-delta mud in the deltaic depositional system. At early stage of progradational delta sedimentation，the isolated mono-genetic sandbodies were developed and the updip tip-out lithologic trap and multi-layered thin sand reverse block-lithologic trap formed. At the middle stage，the superimposed bi-genetic sandbodies were mainly developed and followed by isolated mono-genetic sandbody，and multi-layered reverse block-lithologic trap formed. At the final stage，the multi-genetic incised superimposed sandbodies were mainly developed and followed by bi-genetic sandbodies，and multilayer complex fault block-lithologic trap and block formation unconformity trap formed.From bottom to top，the superimposed pattern shows as the isolated mono-genetic sandbody-superimposed bi-genetic sandbodies-multi-genetic incised superimposed sandbodies.