Abstract: There is some difficulty in the XRD quantitative analysis of attapulgite clay in application to industry. Many previous methods about the quantitative analysis also have some problems in, choosing suitable inserted standard mineral and preparing samples. In this study, palygorskite is purified from attapulgite clay by sedimentation method. Dispersant sodium polyacrylate （PAAS） is used in the experiment so that the aggregation of palygorskite can be dispersed completely. Corundum and quartz are used to prepare a series of mixture samples with 5% interval of palygorskite in the experiment. In all samples, content of corundum is constantly 50%. The National Bureau Standards （NBS） method is employed to prepare the XRD samples. Ratios of integral intensity of palygorskite to that of corundum, labeled as Ip, 110/Icor,113, are calculated with the backgroud value subtracted. A plot is obtained by content of palygorskite as X axis and ratios of Ip, 110/Icor, 113 as Y axis. Linear equation is fitted according to the curve. Feasibility of the linear equation is proved by the study of three samples from Jiangsu, China and the existence of non-crystal materials in the clay is also proved indirectly. The equation can be used in application to the practical industry production.