Naphthalene derived mesophase pitch (NMP) or the NMP reacted with AgBr was spun into fibers, stabilized and carbonized up to 280$0^{circ}C$. The morphological structures of the fibers depend not only on the conditions of oxidative stabilization but also on the AgBr addition in the NMP. The Ag in the fiber was recognized as a catalyst for reduction of activation energy of the graphitization procedure though it created defects during the carbonization procedure destroying the ordered structure. The carbon fiber from the precursor reacted with AgBr, stabilized at 27$0^{circ}C$ and carbonized at 2,40$0^{circ}C$ exhibited maximum conductivity of $1.5 imes$$10^{4}$S/cm.