Abstract: Objective:To compare the effects of osteoclasts on the absorption activities of the bovine cortical bone slices and dentine discs.Methods:Osteoclasts were harvested from RAW264.7 cells induced by 25 ng/ml M-CSF combined with 30 ng/ml RANKL,which was cocultured with bovine cortical bone slices and dentine discs,respectively.The number of positive cells and area of resorption lacunae were detected by antitartaric acid phosphatase staining,and the absorption activities of different substrates were compared.Results:The difference of the TRAP positive cells in different substrates coculture was not statistically significant(P>0.05).The area of resorption lacunae in bovine cortical bone slices was significantly more than that in dentine discs(PConclusions:Compared with the dentine discs,the absorption activity of osteoclasts on bovine cortical bone slices is strong.