SiC/SiC joint materials composed with a single-layer and a multi-layer were prepared to investigate the interfacial phenomena by brazing. The joinings were carry out various temperatures of 760, 850 and 950$^{circ}C$ respectively for 10min. in N2 and vacuum atmosphere. The frit involved Cu and CusilABA were used as joint materials. The analysis on the interfacial were used line profile and point analysis of EPMA. The result showed that the thickness of interfacial reaction layer was 3.6$mu extrm{m}$ of CusilABA 10.8$mu extrm{m}$ of frit and 2.5$mu extrm{m}$ of CusiABA$.$frit which has shown the most thickness at 950$^{circ}C$ in N2 atmosphere. Also same phenomena(CusilABA: 5.5$mu extrm{m}$ frit :11.0 $mu extrm{m}$ of and CusilABA$.$frit : 10,7 $mu extrm{m}$) was occurred at 950$^{circ}C$ in vacuum atmosphere as well. The phenomena was caused by increasing of activities between Ag and Cu reaction with increasing temperature to form buffer layer. Thus the buffer layer was dissipated residual stress to improve the joint strength in the SiC/SiC joint materials