The high performance diamond brazed saw was developed to cut efficiently AZ31 Magnesium Alloy. The Ti-coated diamond and the uncoated diamond were brazed with NiCr alloy by high-frequency induction under argon atmosphere at 1040°C within 20 seconds. Scanning electron microscopy (SEM), energy dispersion spectrometer (EDS) and X-ray diffraction (XRD) were used to investigate the interfacial microstructures between brazed diamond and the filler alloy. The results show that Cr-carbides forms normally and compactly on the surface of Ti-coated diamond brazed, whereas Cr-carbide forms tangentially and loosely on the surface of uncoated diamond brazed. That is because Ti has changed the mechanism of Cr-carbides formed on the surface of diamond brazed. The test of cutting AZ31 magnesium alloy plate shows that the section cut by Ti-coated diamond saw is much smoother than that cut by uncoated diamond saw after a long time.