Dielectric Spectroscopy of conducting Polyaniline polymer H M El Ghanem 1* , H Attar 2 , S Abduljawad 3 and H Sayid Ahmad 2 1 - Physics Department, Jordan University of Science and Tech. Irbid Jordan 2 – Physics Department, Al-Bayt University Al Mafraq Jordan. 3 – Physics Department , Hashimiat University Zarqa Jordan The dielectric spectroscopy of conducting polyaniline polymers (PAN) in th form of emeraldine base and emeraldine salt were carried out in the temperatur range 30 to 80 C 0 and in the frequency range 1Hz to 1 MHz. The imaginary pa of the impedance Z” versus frequency exhibits a relaxation peak , the position o the peaks are shifted towards lower frequencies for concentrations belo 0.1,while the peaks are shifted to higher frequencies for concentrations abov 0.1. The PAN samples were protonated (doped) externally with variou concentrations of aqueous sulfuric acid in the range of 0.05 to 0.5 molar. Th thermal behavior of undoped and doped PAN samples has been analyzed usin thermal gravimetric analysis and differential scanning calorimetry technique reveal that transition in the thermal behavior has been observed fo concentrations above 0.1 molar. The a.c conductivity measurements reveal th insulator to metal transition in the conductivity of these samples was observe for acid concentration greater than 0.1 molar. The a.c conductivity for th protonated samples bellow 0.1 molar follows an Arhenius behavior 0  ∂ ∂ T σ wit two activation energies, while 0  ∂ ∂ T σ for acid concentration greater than 0.1. Key words: Polyaniline, Conductivity, Dielectric constant, Conducting polymers.