Abstract:Sainfoin (Onobryehis viciaefolia Scop) tissue cultures were frozen using the eryoprotectant of 10% DMSO+10% glycerin+8% sucrose at a cooling rate of l℃/min from 0℃ to –35℃—–40℃, kept for 2 hrs followed by storage in liquid nitrogen, and then rapidly thawed in a 40℃ water bath. The survival rate of the stored specimens could be reached to 60–70%, and these cultures still maintained their high differentiation ability. The ultrastructural changes occurred markedly with the different freezing methods: The rapid-freezing and slowfreezing at the cooling rate of l℃/min to –35℃—–40℃, but with out keeping samples for certain time, led cell ultrastructure to be lethally ruptured. The cell injury was reversible when the samples were kept for 30 min at terminal temperature –35℃. The ultrastructure of the samples kept for 2 hrs at –35℃—–40℃ was basically similar to that of the control material. The results further demonstrate that the technological system established previously by us is reasonable and could be used effectively the long-term preservation of sainfoin germplasm.