Abstract: Research on integrating ultrafine grinding with surface modification of attapulgite clay by stirring-type ball mill with stearic acid as modifier and with sodium hexametaphosphate as grinding aid was carried out.Influences of stirring speed,modification time,ball/material ratio,dosage of modifier,and dosage of grinding aid on the effect of grinding and surface modification were discussed.Optimum technical and operation conditions were obtained:stirring speed was 750 r/min,modification time was 40 min,mass ratio ball to material was 4∶[KG-*2]1,dosage of modifier was 4%,and dosage of grinding aid was 0.5%of the mass of attapulgite clay.Under the optimum conditions,activation index,oil-absorbing value,and median diameter d<SUB>50</SUB> of modified attapulgite clay powder were 0.97,0.34 mL/g,and 0.64 μm,respectively.Comparison infrared spectra of attapulgite clay and modified attapulgite clay showed mechanochemistry mechanism and proved the feasiblity of integrating superfine grinding with surface modification.