Abstract: C/C composite is used frequently in aerospace and aviation because of the advantage of light specific gravity, thermostability and so on. The research status of welding of C/C composites was introduced, which includes welding of C/C composites and C/C composites, welding of C/C composites and titanium alloys, welding of C/C composites and super alloys. Brazing has been used most widely in joining of C/C composites. The main problems of the welding was discussed and the research direction of the welding technique was indicated.