Abstract: Clinical defeated porcelain fused to metal(PFM) was analysed.The results indicated that the interface of porcelain fused to Ni-Cr alloy was smooth, reaction layer was not obviously formed, and there cracks and pores existed in PFM. The Ni-Cr alloy and porcelain interface reaction mechanism was studied with scanning electron microscope, energy spectra and X-ray diffraction. The results showed that AlNi₃ and SnCrO compound oxide were produced, and a narrow reaction layer were examined in the interface. The metallurgical bond between Ni-Cr alloy and porcelain was effectively improved, and the interface defects was reduced, and good bonding between Ni-Cr alloy and porcelain was realized.