Dental pulp stem cells of mice (Mus musculus var. albino) (DPSCs) were 'preserved by 2 procedures: (1) 4°C/20mins, then -20°C/30mins, and stored at -80°C
(2) -20°C/30mins, and stored at -80°C. Dental pulp fragments were cultured in 35mm-dish with DMEM/F12, supplemented with 10 percent FBS, 100UI/ml Peniciline and 100ug/ml Streptomycine, at 37°C and 5 percent CO2. The cell viability was measured by trypan blue exclusion method after 1 day, 2 vyeeks, 4 weeks and 8 weeks. Dental pulp stem cells were identified using flow cytometry method. Cultured population of cells (P4) expressed in high level of mesenchymal stem cells as CD73, CD90, CD105 and low level of endothelial hematopoietk cells as CD19, CD34, CD45. The result showed that mice DPSCs were sucessfully cryopreserved by the following procedure: 20°C/30mins, and stored at -80°C in 4 weeks. After thawing, cells adhered, developed and expressed some of the markers of the mesenchymal stem cells such as CD73, CD90, CD105 and did not express some of the markers of the hematoeic stem cells such as CD19, CD34, CD45.