In this article, polyaniline (PANI)/cotton composite were prepared by in situ polymerization on the grafted cotton. First, acrylamide was grafted onto cotton cellulose using a radical graft polymerization process and some influencing factors were studied. Then polyaniline/cotton conductive composite fabrics were prepared by chemical in situ polymerization on the grafted cotton. The influences of the concentration of ammonium persulfate, aniline, hydrochloric acid, and the reaction time to the conductivity and K/S of composite fabric were studied. By contrasting, graft brought on an improvement of about one order of magnitude to the conductivity of composite fabric. The strength, TG, FTIR-ATR, and SEM of prepared fabric were measured. The thermal stability and tear strength of composite fabric reduced, whereas PANT exhibited a rough but uniform, coherent PANT coating on surface of cotton fiber. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1126-1132, 2011