Abstract: By the analysis and study on the sedimentary environment during coalforming period of coalbearing strata in Dongsheng,and by the experimental verification of the adsorption relationship between the kaolinite and organic matter using the organic adsorption experiment,the concentration mechanism of sandstonetype kaolin in Dongsheng is discussed.It is indicated that the concentration and mineralization of kaolinite in the fluvial environment are related to the existence of a lot of organic matter.The humic material produced by the decomposition of plant has the stronger adsorption capacity.Under the conditions of pH>55 and suitable amount of multivalent cations,the humic material in the water medium could be adsorbed firmly each other with the kaolinite and quartz through the multivalent cations,forming the complex of kaoliniteorganic matterquartz,thus,the kaolinite could be transported and deposited along with the quartz.Some organic matters with a certain of hydrophobicity are adsorbed with the minerals,changing the hydrophilicity of mineral particle surface and prompting the deposition and concentration of kaolinite.