The preparation and certification of five China Sea and continental shelf sediment reference materials MSCS-1- 5 are reported. The raw samples were collected separately from the East China Sea and the South China Sea. First,they were ground by a ball mill to a homogenous powder of less than 74μm,then these samples was further processed by an ultra-fine processing technique,a jet mill,to form an ultra-fine powder. The particle size distribution of the samples was determined with a laser particle-analyser,their average particle size is < 4μm. The homogeneity was tested by high-precision WD-XRF and the minimum sampling mass is 5 mg,which was confirmed by XRF,ICP-AES and ICP-MS. Twelve laboratories participated in the cooperative study and 60 constituents were determined. 50 and 51 components were certified as certified values and 1 and 2 components as reference values respectively for MSCS-1 and MSCS-2,52 constituents were certified as certified values for MSCS-3,4 and 5. The sum of the major and minor components in the five reference materials MSCS-1 -5 is 99.9% ,99.6% ,100.4% ,100.1% and 99.7% ,respectively.