Basing on generalization of large actual material on complex investigation of diamond, its characteristic in Upper Paleozoic and Mesozoic sedimentary thick layers of the Siberian platform is provided. This allowed obtaining new data on composition features and distribution of diamond in recent sediments of main diamondiferous regions of Lena-Anabar, Central-Siberian and Tungusskaya sub-provinces. Special attention is paid to the Central-Siberian sub-province, where it is convincingly shown that the area of development of individual diamond macro-associations is limited by a specific diamondiferous region. Identified in some diamondiferous regions proximity of typomorphic features of diamonds in sedimentary thick layers of these ages testifies that formation of these collectors was due to washout of more ancient productive layers or Middle Paleozoic primary sources. T was noted that a polygeny of mineralogical associations of diamonds from different in age placers within some diamondiferous regions might be successfully used for forecasting and prospecting primary sources.