This paper focuses on the electrical conductivity and dielectric properties of HCl doped polyaniline under various heat-treatment temperatures. Using differential scanning calorimetry (DSC), FT-IR spectra, and X-ray diffraction (XRD), it is discovered that PANI-HCl appears an excellent electrical conductivity below 120 degrees C; as the temperature rises to 160 degrees C, its electrical conductivity drops sharply and is almost like a dielectric. Furthermore, PANI-HCl demonstrates an excellent dielectric constant below 100 degrees C and a loss tangent tan(delta(epsilon)) between 0.35 and 0.49, when the temperature increases to 140 C, the dielectric constant decreases rapidly and the loss tangent falls below 0.1. HCl volatilization and changes in the molecular chain also have a distinct influence on the conductivity and dielectric properties.