Joining of Si3N4 / Si3N4 was carried out by using Cu68Ti20Ni12 fill metal. The results show that brazing temperature and holding time have an important influence on joining strength, and the highest strength value (289 MPa) was achieved at the brazing temperature of 1 373 K for 10 minutes. Microanalysis of the Si3N4/ Cu68Ti20Ni12 interfacial region showthat Ti and Ni concentrate towards Si3N4 and the enriched area of Ti is closer to Si3N4 ceramics, while Si diffuses towards braze layer and Cu element is concentrated in the center part of the joint; Interfacial region has two reaction layer. Reaction layer I is TiN while reaction layer II consists of TiN, Ti5Si4, Ti5Si3, Ni3Si and NiTi compounds .