The objective of this research was to elucidate how specific membrane surface functionalities affect fouling by alginate in seawater desalination. Alginate adsorption on self-assembled mono-layers with -COOH, -NH 2 , -CONH 2 groups under different solution conditions was studied using quartz crystal microbalance with dissipation monitoring. Cross-flow filtration experiments were performed using four commercial RO membranes to study the correlation of alginate fouling to membrane surface properties. Experimental results revealed the importance of solution condition, but surface functionality did not have significant impact on alginate adsorption equilibrium. The initial adsorption/deposition rate on the -COOH surface was the highest., while adsorption on the -NH 2 surface was most difficult to remove by surfactant cleaning. Filtration experiments showed that alginate fouling was more closely related to surface roughness than surface chemistry. The results suggest that surface chemistry is not an important factor for short term membrane fouling in seawater RO processes.