Abstract: The influence of boron and chromium on wettability of nickel-based high temperature filler metals on carbon fiber reinforced silicon carbide composite (3D-C_f/SiC)was studied.It was found that at 1 200℃ for 10 min under vacuum when the content (wt,%)of chromium equals to 15% and boron equals to 0.6%, the contact angle of nickel based filler metal on C_f/SiC is 10 degree. While, as the content of boron adds to 2.4%, the angle increases to 62 degree.It indicates the boron reduces thewettability.The experiment results indicates the element chromium can promote wettability greatly.The wetting procedure is reactive wetting, and several carbides and silicides were formed at interface.