Abstract: Based on the experimental results of adsorption and wettability, it is concluded that the adsorption of sodium oleate on γ-Fe₂O₃ from aqueous solution is of multilayer. The molecules in the first layer are chemisorbed with their hydrocarbon chains extending outward. At higher concentration the second adsorption layer forms and converts the particle surface into hydrophilic again. The wettability of particle surface was found to be related directly to the stability of bothe aqueous and nonaqueous suspensions.