Abstract: The polyaniline was synthesized by chemical oxidative polymerization method with ammonium persulfate(APS) as oxidant and hydrochloric acid(HCl) for protonation of aniline.The influences of the mol ratio of oxidant to aniline,the concentration of hydrochloric acid,reaction temperature and reaction time on the conductivity and yield were studied.The structure and morphology of polyaniline were researched by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transform infrared spectrophotometer(FT-IR),ultraviolet-visible spectrophotometer(UV-Vis) analysis ways.The optimized experiment conditions is determined as follows.Mol ratio(ammonium persulfate to aniline) is 1:1,hydrochloric acid concentration is 1 mol/L,reaction temperature is 5℃,the reaction time is 6 h.Under these conditions,the yield reaches more than 95%,the conductivity is over 27 S/cm.The conducting polyaniliner exhibits certain crystallinity behavior.