This paper studies the discrimination indices on the ball clay,and analyzes the advantages and defects of the existing indices.Collecting the physical and mechanical indices of the ball clay from the recent years’waterway dredging engineering of TDC,this paper analyzes the data by correlation,variance analysis,and comparative statistics.Combining with the engineering practice of TDC,this paper sums up some indices on the ball clay,based on which,the discrimination indices,which shows the applicability in a certain range,is verified with the measured values.