Initial fouling behavior due to membrane-foulant interactions was investigated by atomic force microscopy for various reverse osmosis membranes with different surface properties. Carboxylate modified latex and unmodified latex particles were used as surrogates of organic foulants. The results showed that the membrane-foulant adhesion forces were mainly governed by membrane surface properties such as hydrophobicity and surface charge. Stronger adhesion forces were determined for the membranes with more hydrophobic and less surface charge. Fouling experiments were further carried out to correlate the adhesion force data to actual flux-decline curves. A remarkable correlation was obtained where the membranes with stronger adhesion force more suffered from flux decline.