Abstract: Optical microscope(OM),X-ray diffraction(XRD),electron probe micro-analyser(EPMA) and energy disperse spectroscopy(EDS) were used to analyze the phase composition and microstructure of five kinds of nickel-based brazing filler metal with different chemical compositions. The results showed that phase compositions and microstructure of the five kinds of nickel-based brazing filler metal were different to a certain degree,but microstructure of them all were nickel solid solution and compound eutectic.