Abstract: Organically modified attapulgite clays were prepared using sodium oleate as modifier. The influences of sodium oleate concentrations, pH values and temperatures on the organification reaction were investigated. The physicochemical properties of raw attapulgite and organo-attapulgite clays were characterized by infrared spectroscopy, rheometer and ζ potential. The results showed that the organification degree of attapulgite increases with increasing the concentration of sodium oleate, while the organification degree firstly increases with increasing pH value, reaching a maximum and then decreases. No obvious influence of temperature on reactions can be observed. The infrared spectroscopy showed that oleate anions were already adsorbed onto attapulgite surfaces. The rheological and electrokinetic properties showed that the viscosities of suspensions modified by different levels of sodium oleate were controlled by electrostatic and steric interactions, and the lowest viscosity of suspension was obtained when 4.56% sodium oleate was added to the suspension.