The influences of various carbonization temperatures on electrical resistivity and morphologies of polyacrylonitrileobserved by a scaning electron microscope. The electrical resistivity behaviors of the webs were evaluated by a vol-ume resistivity tester. From the results, the volume resistivity of the carbon webs was ranged from 5.1×101 Ω·cm to3.0×102 Ω·cm, and the average diameter of the fiber webs was varied in the range of 310 to 160 nm with increasingthe carbonization temperature. These results could be explained that the graphitic region of carbon webs was formedafter carbonization at high temperatures. And the amorphous structure of polymeric fiber webs was significantlychanged to the graphitic crystalline, resulting in shrinking the size of fiber diameters.