Formylated polystyrene (PS-CHO) was synthesized by chemical modification of polystyrene (PS) for the fabrication of honeycomb patterned (HCP) porous PS films with aldehyde group functionalized pores via breath figure method under humid conditions, The incorporation of hydrophilic aldehyde group affected the hydrophobicity of PS solution and assisted the self-assembly of PS-CHO toward pore. The presence of aldehyde groups in the films were proved by the post treatment with Tollens's reagent, which results in silver decoration at pores. The morphology of the films before and after silver decoration was studied by scanning electron microscopy analysis. The pore selectively self-assembled aldehyde groups in the patterned porous films can have many applications as a reactive substrate in biomaterials and chemical moieties adhesion. (C) 2018 Wiley Periodicals, Inc.