Abstract: Objective： To evaluate the occluding effect of bioactive glass combined with Er laser irradiation on dentinal tubules. Methods：45 dentine discs were prepared and etched with 0.5 mol/L EDTA. They were randomly divided into 5 groups with different treatments: Group A(without treatment as control), Group B(treated with bioactive glass) , Group C(treated with Er,Cr:YSGG laser irradiation), Group D(bioactive glass followed by Er,Cr:YSGG laser irradiation), Group E(Er,Cr:YSGG laser irradiation followed by bioactive glass). The occluding effect and mineral content was examined by scanning electron microscopy (SEM) and X-ray energy spectrum analysis (EDXA). Results： Micrographs of SEM showed obvious occluding effect in Group B,C,D and E,with the best effect in Group D, and the dentinal tubule exposure rates were Group D