The objectives of this 2 year study of the interfacial and mechanical properties of Carbon-Carbon Composites are: (1) to find effective surface treatments and de-treatments which would lower the chemical bonding and increase mechanical bonding and interfacial coefficient of friction; and (2) to determine the correlation between surface functional groups and the mechanism of load transfer from fiber to matrix, interfacial bond strength and fracture toughness. The fiber surface treatments will include oxygen, argon plasma etching and nitric acid treatment. The surface characteristic of treated and untreated fibers will be determined using Electron Spectroscopy for Chemical Analysis and Fourier Transform Infrared Spectroscopy. The C-C composites will be produced using both treated and untreated fabrics. All the composites will be analyzed using electron microscopy, destructive and non-destructive mechanical testing. The resulting mechanical properties will be correlated with the surface properties of the fabrics. This study will answer the fundamental question related to synergetic mechanism of the matrix by employing weak chemical bond, mechanical bond and high coefficient of interfacial friction. In addition, the results of this research will assist in the optimization of mechanical properties of C-C composites, increasing their chances for wider technological applications.