Sodium modification of bentonite was investigated by use of NaF,NaCl,Na2CO3,and organic modification of bentonite was investigated by use of octadearyl trimethyl ammonium chloride (1831),octadearyl dimethyl benzyl ammonium chloride (1827) and hexadecyl trimethyl ammonium chloride (1631).Conditions of sodium and organic modification were studied,the technology of preparing bentonite grease were examined.The results show that the sodium modification effect is better under the condition of Na2CO3 content 2% to 3% ,the temperature between 60 ℃ and 80 ℃,the time between 30 minute and 60 minute.The onganic modification effect by 1831 or 1827 blending with 1631 is better.The bentonite greases prepared by modified bentonite possess good properties,such as high temperature property,colloidal stability,mechanic stability,antirustproperty,anticorrosion propert,waterproof property,extreme pressure and antiwear property.