Electronic processes in carbon fiber have been studied. Experimentation was madeon the thermoelectric effect and the transverse magnetoresistance effect at temperatures between 77 K and 300 K. The absolute thermoelectric power (S) is positive and exhibits a monotonical increase with temperature, while the magnetoresistance (Δρ/ρ) is negative in the magnetic field (H) range examined (≤15 kG). There is found, however, an indication that Δρ/ρ reaches a minimum at H not much exceeding 15 KG. In terms of the conventional two-band scheme, these observations imply that the Fermi level is pretty much depressed into the lower π-band, and hence positive holes are of absolute majority. Some analytical discussions are given on this basis.