Many of applications of C/C composite are in brake discs for aircraft and other high performance civil and military aircraft where these composites have replaced sintered metals by virtue of their low density and superior thermal performance. However, the utilization of C/C composites are restricted by the need for an inert environment and long processing time. In this study, 2-D C/C composites were heat-treated(650$^{circ}C$, 800$^{circ}C$, 950$^{circ}C$, 1,100$^{circ}C$) within 10 hrs and made by resin impregnation method with carbon mat and phenolic resin matrices. The variation of weight has an influence on shrinkage and thermal expansion of the matrices during the carbonization.