The Pb enrich not only in shallow continental shelf area of main river mouths,but also in central deep sea basin area due to the granularity affect of surface sediment in the South China Sea. Calculating the background values show that the values in continental sloping area (21.18×10-6±12.64×10-6) are roughly the same to the measured values of the pole samples in this area; the values in deep sea basin area（27.87×10-6±7.82×10-6) are less than the pole sample's; the continental shelf area's（19.57×10-6±19.95×10-6）are less than China coastal zone's; the whole area's（22.87×10-6±14.54×10-6) are near to the shale average's; and the deep sea basin's（27.87×10-6±7.82×10-6) are much less than modern abyssal clay's. The above characteristics indicate that the Pb contents of surface sediments are in natural change range, and most of samples' are in normal change range. Geoaccumulation index (Igeo) and enrichment factor(EF) show that the surface sediments of the South China Sea are nonpollution Pb in whole, but lowgrade pollution of sediments are in the Pearl River Estuary and shallow sea area of southwestern Taiwan island. It indicates the different sea areas have the similar Pb sources thatthe Pb isotope ratios have the same change trend in continental shelf area, continental sloping area and deep sea basin area. And it indicates continental Pb of the Yangtze Block are transported to the South China Sea by Red River, Mekong River and Pearl River,etc that the Pb isotope composition of surface sediments in the South China Sea inherit the Yangtze Block's, and its isotope ratios are in the range of Kfeldspar's in Red River and Mekong River.