PFO(pyrolized fuel oil) and $C_{10}^{+}$ oil, which are the residual heavy oils form a NCC(naphtha cracking center), were heat-treated to produce the precursor-pitch for carbon materials. After PFO was initially distilled near $300^{circ}C$ to separate the volatile matters recovering as high-quality fuel oil, the residuum of nonvolatile precursor-pitch was then thermally pyrolized in the temperature ranges from $350^{circ}C$ to $450^{circ}C$. Spinnable isotropic pitch with the softening point of $200^{circ}C$ and the toluene insolubles of 36wt% was obtained at $365^{circ}C$, and then was successfully spun through a spinneret(0.5mm diameter). After spinning, an isotropic carbon fiber of $25{mu}m$ diameter was obtained via oxidation and craboniation procedures. Mesophase spherules began to be observed from the product pitch pyrolized at $400^{circ}C$, and bulk mesophase with a flow texture was observed above $420^{circ}C$. In the case of $C_{10}^{+}$ was the feed was polymerized in the presence $H_2SO_4$ at room temperature to increase the molecular weight and then heat-treated gradually up to $200{sim}250^{circ}C$. The products obtained with the softening point of $80{sim}190^{circ}C$ were carbonized at 500 and $1000^{circ}C$ to examine the morphology.