Resorcinol-formaldehyde(RF) gel films were synthesized by a series of processes such as sol-gel, supercritical drying and carbonization using resorcinol and formaldehyde. The main factors that affect the properties of aerogels such as HAC content and the reaction temperature were investigated to indicate the mechanism of self-assemble RF films. The micro-morphology and structures of the gel films were characterized by FT-IR and SEM. It was found the thickness of RF aerogel films is about 50 μm , the size of particles about 10 μm and there are no obvious holes. The results show that RF gel self-films form when the mass fraction of resorcinol and formaldehyde in the solution are 67% and the sol is acid. The process and mechanism of RF gel self-films are similar to the process of RF gel and