In this study, the effect of nanosilica and boron carbide on the adhesion strength of a phenolic resin for graphite bonding was studied. The adhered specimens were cured at 250 degrees C and then heat treated to examine the thermal resistance in the range 200-1000 degrees C. Then, the adhesion strength of specimens was examined by a tensile method. The chemical structure of bonding and possible carbonization was examined using Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA) was employed to determine the char yield, and X-ray diffraction (XRD) was used to study crystalline phases at different temperatures. The elemental analysis and morphology of the adhesive bond were investigated using energy-dispersive Xray spectroscopy (EDS) and scanning electron microscopy (SEM), respectively. The results showed that sintering of reformed boron carbide and amorphous carbon above 800 degrees C resulted in a significant increasing in adhesion strength at 1000 degrees C.