We develop a novel heterogeneous pattern with nanometer-sized spots surrounded with a bio-inert matrix by using a diblock copolymer thin film. The nanopattern with features down to 20 nm is highly resistant to protein adsorption and cell adhesion. By providing a domelike topography similar to biologically relevant size, such a heterogeneous nanopattern demonstrates an excellent anti-biofouling property to control protein-surface and cell-surface interactions at the molecular level.