Abstract: Using low-grade bentonite from Shouguang as raw materials,the montmorillonite content were raised from 76% to 90.5% after artificial choose and wet purification process.NaF and Na₂CO₃ as Na-agent,the spacing between the adjacent silicates layers of Na- montmorillonite is 1.262nm w ere det ermined by XRD.The high quality organic bentonite were prepared from Na-bentonite,Using CTAB as an intercalating agent,the apparent viscosity was 1214MPa·s,so it can be satisfy the needs of high-viscosity organic bentonite.Increase in the spacing between the adjacent silicates layers from 1.26nm to 4.010nm were determined by XRD.FTIR showed that the CATB was intercalated into the interlayers of montmorillonite easily.The flake of montmorillonite is loosed in SEM.The organic modification effect was well.