Abstract: Organic-bentonite was prepared by using cetyltrimethyl ammonium bromide(CTMAB) as modifier.Its microstructure were characterized by XRD.The adsorption of organic-bentonite on methylene blue was studied.The results showed that the adsorptive percentage of methylene blue reached 98.69% under the condition of adsorption：thickness of methylene blue is 40 mg/L,the dosage of wastewater and organic-bentonite respective is 200 mL and 2 g，at weakly acidic and  reaction time is 40min in room temperature and weakly acidic .The performance of organic-bentonite for adsorption of the methylene blue is better than Ca-bentonite.The adsorption ability  of organic-bentonite is strong.

Key words: Modification, Organic-bentonite, Methylene blue, Adsorption