Abstract: Energy dispersive X-ray spectroscopy (EDX) is a kind of analysis method used in researching the adhesive joint and polymer composite surface and interface characters The changes of the adhesive/carbon-carbon composite joint surface and interface at different temperatures were researched by EDX The results indicate that carbon element content on C-C composite surface in Z direction is less than that in X and Y directions from room temperature to 900℃, which was decided by the characters of C-C composite The break form of the adhesive/carbon-carbon composite joint is changed from C-C composite break at room temperature into adhesive break at higher than 200℃ The changes of carbon, oxygen and silicon elements content on the adhesive and C-C composites surface indicate that the heat decomposition speed of the adhesive is almost the same as that of C-C composite under 550℃，but above 550℃ the adhesive decomposition speed is faster than that of C-C composites