Micro-patterned composite films consisting of bowl-like tin dioxide (SnO₂) microparticles with smooth surfaces and well-defined shapes were prepared by the breath figures method using a homogeneous solution of tin (IV) chloride/polystyrene/chloroform (SnCl₄/PS/CHCl₃). The samples were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The shape and size of SnO₂ microparticles could be adjusted by varying parameters of concentration and relative humidity. A possible mechanism was proposed for illustrating the formation of composite films with bowl-like SnO₂ microparticles. The present strategy for the fabrication of bowl arrays offers new prospects for the application in biosensors, microreactor, and microfluidic devices.