Abstract: Based on a large amount of data from geotechnical investigation and soil test in Majiatian Tailings fill dam,the paper makes a thorough analysis of hydrochemical field of dam body as well as the property,filling characteristics and law of change of tailing.The paper also studies the law of distribution,of changes of physical and mechanical properties as well as the relation between shear strength and grain size distribution of Majiatian tailings,which shows that the Majiatian tailing has higher shear strength.