We describe a simple yet extremely versatile and generalized surface polymer modification approach based on a surface initiated polymerization from a polydopamine (PDA) layer. PDA deposits on virtually any substrate independent of specific surface chemistries and can act as a photoinitiating layer to initiate the radical polymerization of a variety of (methyl)acrylic/styrene monomers. It does not require any metal/ligand catalyst, additional photoinitiator or dye sensitizer. Another attractive feature of this novel strategy is the ability to spatially control the architectures (pattern, gradient) of the polymer films by altering the areas of light irradiation. It is also adaptable to large area grafting with an ultra-small amount of monomer solution (a thin monomer solution layer).