Abstract: PURPOSE To investigate the influence on the sintering densification, microstructure and transformation behavior of tooth-like yttria-stabilized tetragonal zirconia polycrystal by adding rare-earth oxide as colorants. METHODS Six kinds(S1,S2,S3,S4,S5,S6) of tooth-like yttria stabilized tetragonal zirconia polycrystal(Y-TZP)were made by introducing internal colorating technology, the relative density of sintered specimens was determined by the Archimedes method. Scanning electron microscope (SEM) was used to examine the surface morphology and determine the grain size. The phase identification of sintered samples was carried out by X-ray diffractometer. RESULTS The relative density of the six kinds of tooth-like yttria stabilized tetragonal zirconia polycrystal were over 98%，through SEM images of the cross-sectional surfaces, the grain size of the six kinds of sintered composites were observed in a wide range from 100 nm to 300 nm, a second phase was not detected in the grain boundaries. The diffraction peaks of the main phase were observed as tetragonal phase.CONCLUSIONS Tooth-like yttria-stabilized tetragonal zirconia polycrystal was acquired with better mechanical property by adding rare-earth oxide as colorants, and was available for clinical application.