By using the new methodology of synthesis of container structure, we demonstrate the ability to control an improved ice-templating method to synthesis of polyaniline (PANI) in the form of hemisphere. The influence of the synthetic parameters, such as the concentration of doping-acid, oxidant, and aniline on the morphologies of PANI structures, has been investigated. It is determined that the doping acid and the second solvent added (such as diethyl ether absolute) have great positive influence on the formation of product's micro-morphology. The structure and morphology of PANI hemispheres are characterized by Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD) patterns, energy-dispersive X-ray analysis (EDX), optical microscope images, and scanning electron microscope images (SEM). The formation mechanism of hemispheres in this article is well suggested. PANI hemispheres have super performance in sensitivity, time response to NH3 compared with traditional polymerization at room temperature. This work extends the field of functional materials with complex container structure and offers a new green route to synthesis of hemispherical container structure. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3596-3603, 2010