Defined spatial localization of biomolecules on the polymer surface Is potentially powerful method to generate biocompatible surface. Photolithography and photochemistry can be used to immobilize peptides only al a given region of the surface. In this study, peptide RGDS, one of the endothelial cells recognition sites of fibronectin, was covalently immobilized on the polystyrene coated surface with micropattern. It was performed by photochemical reactivity of a synthesized N-hydroxysuccinimidyl phenyl azide. The micropatterning was confirmed by staining with fluorescent dye, aminoacetamido fluorescein. Endothelial cell adhesion was observed only on the RGDS immobilized areas.