AbstractPolyaniline (PAn)-coated conductive paper was prepared by in-situ polymerization of aniline and a two-step process. XPS results confirmed that the bond between PAn and cellulose existed in the form of hydrogen bonding. The mild treatment did not result in the oxidation and degradation of cellulose. Decreased bonding strength of conductive paper was attributed to the coverage of hydroxyl groups on pulp fibers by PAn. For the PAn-coated paper about one in every three nitrogen atoms was doped with p-toluenesulfonic acid (PTSA). The quinoid imine nitrogens of the PAn molecular chain were preferentially doped. Pulp fibers seemed to be favorable for the doping of PAn with PTSA. The surface resistivity sharply decreased at least two orders of magnitude with a very small increase in the amount of PAn coated (from 3.6% to 4.2%). A continuous conductive network was formed and the surface resistivity was lowest when the amount of PAn coated reached 30.1%. The upper and lower threshold values were around 4% and 30%, respectively. SEM study showed that the shape of the PAn coated on pulp fibers was spherical with a diameter from 100 to 200 nm.