| The study area is located in the western South Yellow Sea (33.5°-36°N, 119°-122°E). It is of great significance for understanding the dynamics of modern sedimention process of the coastal zone and the river effect on offshore sedimention as well as the sediment provenance. Using the data of grain-size distribution, clay mineral compostion and mayor and trace elements characteristics of the surface sediments samples colleted from the area, This paper discuss the sedimentary environments, sedimentation processes and sedimentary sources in the study area.Grain size analysis of the 486 surficial samples from the study area is carried out using the laser grain size analyser. According to Fork's classification(1970), sediments in this area could be divided into gravel, silty sand, sandy silt, silt, sandy mud, mud, with silty sand and sandy silt as the major. The sedimentary environment and the sedimentary sources are the major factor that dominate the characteristics of the surface sediments in the study area.Chemical analysis is made for the major elements and trace elements of the surficial samples from the study area.The results show that most of the elements have similar chemical behavior in the hypergene environment. They generally comply with the rule which the grain size dominates the distribution of the elements. Major elements Ti, Fe, Mg and Al are correlated positively with many elements, which show that they have same provenance. Trace elements Li, V, Cr, Co, Ni, Zn exhibit notable positive correlation between each other, which show that they have same chemical behavior. In REE distribution patterns, the chondrite-normalized REE partition curve incline to the right, indicate that they are enriched in LREE and middle degree Eu negative abnormity. The North American shale and upper continental crust normalized REE partition curve both of even type, indicate no negative Eu and Ce anomaly.X-ray diffraction analysis is made for 482 clay mineral samples selected from surficial sediments. The results show that the clay minerals combination style mostly is illite-smectite-chlorite-kaolinite. The style is same with the Yellow River's.This paper analyzes the shallow sedimentary characteristics by many typical downcores that recovered from the the study area. The outcomes show that the calcretes have formed in the late Pleistocene, and have exposed in the sea floor by the sea water erosion in the eary Holocene. The silty sand and sand have offshore characteristic in the study area, and they have formed in the offshore hypergene environments of Holocene. The Yellow River injected into Yellow Sea through the northern Jiangsu Province in the 1128-1855, and formed a tremendous old subaqueous Yellow River delta. Some of the delta covered the relicts which have formed in the transgression of the Holocene. This paper deduce the sandy silt in the north-east is distal sediments of the subaqueous clinoform arround the Eastern Shandong Peninsula by the limited datum. And it also covered the relicts which have formed in the transgression of the Holocene.In the last, this paper analyze the sediments sources of the weastern South Yellow Sea by clay minerals, ratios of elements, the chondrite-normalized REE partition curve, stepwise discriminant analysis, discriminant function and carbonate. The conclusion indicate that the surfacial sediments are from Yellow River in the study area. One is from the mordern Yellow River which is tansported by the Yellow Sea Current. the other cames from the Old Yellow River Delta. Moreover, the sediments resulting from the erosion of Shandong Peninsula,adjacent area bedrock and Lianyungang by sea water also contribute to the north-east and the Lianyungang sediments respectively.
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