This study presents a very simple method to fabricate organic-inorganic asymmetric colloid spheres. In this approach, when silica particles are used as the Pickering emulsifier to stabilize the monomer droplets (styrene) in water via acid-base interaction between silica particles and auxiliary monomer (1-vinylimidazole), the exposed surfaces of silica particles are very easy to be locally modified with 3-(trimethoxysilyl)propyl methacrylate. When water-based initiator is added, polystyrene-silica asymmetric colloid spheres are highly yielded. The sizes of silica and polymer particles can be tunable. These organic-inorganic anisotropic colloid spheres can self-assemble into an interesting thickness-dependent film. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 3272-3279, 2011