Our new method, presented here for the first time, demonstrates the possibility of storing a human periodontal ligament (PDL) in a frozen state over a period of 3 days with the perio-dontal membrane remaining viable, enabling the thawed tooth to heal with a normal perio-dontal ligament. The final temperature, incubation at -5 oC and the intensity of the magnetic field for the freezer were examined. Cells were cryopreserved for 3 days at -150 oC and the number of survived cells were counted by trypan blue stain solution. When -30 oC was used as the prefreezing temperature, the number of survived cells was over 90%. The intensity of the electric current required to generate a magnetic field was 75mA. From the results, pre-serving not only PDL cells but also valuable cells in high order is possible.