Abstract: Polyphenylacetylene(PPA) were prepared with anhydrous AlCl_3 as catalyst,and sulfonated by concentrated H_2SO_4.The conductivity of PPA/carbon nanotubes(CNT) and sulfonated PPA/CNT composites prepared by mixing CNT with polymer in tetrahydrofuran under sonication were studied.The(result) shows that the room temperature conductivity of the two kinds of composites is enhanced with the (ratio) of CNT increasing,the estimated percolation threshold of sulfonated PPA/CNT is 1% less than that of PPA/CNT,and the amount of CNT that are added to PPA for obtaining the maximum conductivity is 10% of that of the sulfonated PPA.The XRD suggests that the CNT effects the crystal structure of the polymer by interface action.