In this work, the self-assembled nanostructures of chitosan on mica surface formed from various solvents were investigated by using atomic force microscopy. The effects of various factors on the self-assembled nanostructures of chitosan on mica surface, including solvents, the concentration of chitosan, the pH of solution and the drying temperature, were explored in detail. Our experimental data resulted in the conclusion that chitosan molecules could self-assemble on mica surface to form various nanostructures such as nanoparticles, fibril and film. Nanoparticles were always formed on mica surface from CCl4, C6H6, CH2Cl2 solution, fibril preferred to form on mica surface from CH3CH2OH and CH3OH solution and the optimal solvent to form film was found to be CH3CN. Low concentration, pH and temperature were helpful for the formation of nanoparticles, medium concentration, pH and temperature resulted in fibril and high concentration, pH and temperature were often beneficial to forming chitosan films. The study of self-assembled nanostructures of chitosan on mica surface would provide new insight into the development of chitosan-based load-bearing materials. (C) 2015 Elsevier B.V. All rights reserved.