Specialty polymers have important commercial markets in the aerospace, information technology, electronic industries and biomedical applications. A number of electoractive polymers have been the object of increasing academic and industrial interest during the past twenty years. Substantial progress has been achieved in the development and characterization of what is called the synthetic metals (or organic polymer conductors),In the frame work, polyaniline was selected in the presented paper, to be synthesized and studied.lt was prepared via the catalytic Oxidation of aniline in acidic medium using ammonium persulfate in hydrochloric acid. The variation of the electric conductivity of the prepared polymer was correlated with the molar ratio of aniline to to the oxidant under the experimental conditions.' The polymer was investigated by several physical and analytical techniques, the results of the work were given, explained and discussed.