Objective:To observe the effect of the cryopreservation of human peripheral blood stem cells(PBSC) by -80℃ non rate-controlled freezing. Method:We mobilized and collected peripheral blood stem in common methods ,froze cells with 120 g/L HES and 10% DMSO and 10% human plasma of AB type without rate-controlled and preserved them at -80℃.Typeran blue viability and recovery rate of mononuclear cells (MNC), CD34+cells, colony-forming unit-granulocyte macrophages(CFU-GM) were detected before and after cryopreservation in different periods.Result:Having been cryopreserved from 15 to 720 days at -80℃, there were no statistically significant differences in trypan blue viability and MNC recovery rate (P0.05). Although recovery rate of CD34+ and CFU-GM decreased obviously after cryopreservation for 240 days (P0.05), the recovery rate was 82.5% and 79.6%, respectively.After corresponding pretreatment, twenty one patients received transfusion with -80℃ cryopreserved PBSC which had been stored for 12 to 46 days (mean 29 days) and hematological reconstitution was obtained successfully in 14 to 27 days (mean 20.5days).Conclusion:-80℃ non rate-controlled freezing method could be suitable to human PBSC short-term cryopreservation with the cryoprotectant composed of 60 g/L HES and 5% DMSO and 5% human plasma of AB type.