A novel method for the patterning deposition of conducting polyaniline (PAn) on a transparency substrate was presented.A picture or a drawing was printed on a transparent film by a standard laser printer,and PAn was in-situ polymerized on it for three times.Then the transparency was sonicated in toluene or benzene for 20 s,the printed part was removed and a dupe reverse pattern appeared.In order to investigate the capability of patterning deposition,a dupe reversal of a laser printed photo was produced,which was more difficult than line patterning (LP).It showed that the details of the original photo were reproduced,although the contrast was not so perfect due to the transparence of the PAn film.It meant that the in-situ polymerization of PAn could produce rather complicated and delicate patterns,and was prospective to apply in the manufacturing of organic electronics,especially for some disposable plastics/paper electronics.The effect of HClO 4,HCl and toluenesulfonate dopants on the quality of PAn film was studied.