Abstract: The magnetoresistance of C/C composite was studied in different measuring orientation. The magnetoresistance varies with the measuring orientation; the maximal magnetoresistance was found in different orientation for the materials that have different structures and different technics. Graphitized materials have positive magnetoresistance, and non-graphitized materials have negative magnetoresistance, but both of its absolute value increase with temperature rising. Magnetoresistance-temperature is a linear function in every measuring orientation. When the temperature is high enough, some materials' magnetoresistance will keep unchanged. By regressing the magnetoresistance-temperature curves, the slopes of the obtained equations are equal but the intercept is unequal. The magnetoresistance of every orientation is ranged, and dissimilar orientation serials are found for different materials. When the intensity of the magnetic field changes, the value of magnetoresistance changes, but the orientation serial does not change.