Objective To obtain highly enriched osteoclasts in vitro. Methods The bone marrow cells of 1-day, 12-day, 24-day and 36-day old Sprague-Dawley（SD） rats were separately cultured with the presence of 1,25-（OH）2D3 and dexamethasone, and the osteoclast-like cells were identified by Trap staining and scanning electron microscope observation and were purified by trypsin digestion. The count of Trap positive osteoclast-like cells was analyzed statistically. Results The osteoclast-like cells of each group were Trap positive cells and could form the bone absorption lacunas in vitro. The amounts of osteoclast-like cells were different statistically between the groups（P0.05）. Highly enriched teoclast-like cells were harvested by the digestion of 0.25% trypsin and 0.02% EDTA. Conclusion It′s indicated that a large amount of highly enriched osteoclast-like cells could be obtained through the culture of bone marrow cells of 10-day and 12-day old SD rats with 1,25-（OH）2D3 and dexamethasone and the digestion of trypsin/EDTA.
