Polyaniline and its derivatives have high antioxidative stability and are considered to belong to the most useful conductive polymers for practical application. In this work, we have linked 1,4-phenylenediamine to poly(styrene-co-chloromethylstyrene) and prepared poly(styrene-cop-aminoanilinemethylstyrene), poly(S-co-PAAMS). Polystyrene-graft-polyaniline, (PS-g-PANi), has been synthesized by adding solution of ammonium persulfate and p-toluenesufonic acid in water. The conductivity of these polymers was measured by the four-point probe method. The copolymers produced exhibit electrical conductivity comparable to that of polyaniline. PS-g-PANi was also exposed to some cyanide compounds such as hydrocyanic acid (Hydrogen cyanide-HC), ethanedinitrile (Cyanogen-CY), cyanogen chloride (Chlorocyan-CC), and cyanogen bromide (Bromocyan-BC). The cyanide compounds are classified as blood agents groups, in terms of chemical warfare agents standards. First, we prepared different concentration of blood agents at 50, 100, and 150 ppm and exposed them on PS-g-PANi for 2 min. Second, we have drawing conductivity change curves versus time and produced optimum conductivity versus time taken. (c) 2006 Wiley Periodicals, Inc.