In order to identify the effect of agricultural use on clay minerals and nutrient of soil,the study of modern agriculture use of black soil in Northeast China has lasted for 8 years.Clay mineral composition and nutrient of black soil were investigated.The results showed that the weathering process of the black soil was strengthened.The content of silt fraction between 0.002 and 0.02mm was significantly decreased,while the content of clay fraction increase was not significant for soil erosion.Soil exchangeable ion activity was strong,degree of acidification was increased,organic matter content decreased,and the nutrient holding capability decreased.The content of illite in soil was significantly lower,while the content of kaolinite and montmorillonite were significantly increased.The content of S / I mixed-layer mineral is higher than before 8 years.Soil clay minerals were a very sensitive type colloid,and its changes affected soil fertility characteristics.