Individual vegetative cells of Porphyra yezoensis were obtained by mechanical smashing, The isolated cells were oultured In enriched soawster and developed into new fronds in 20 days. The survial rate was about 33%.In attemping to make use of the tatipotency of the vegetative cells of this alga to meet the ever increasing demand for seedlings in commercial culture.A series of experiments were carried out involving the freezing of the seaweed and keeping it at -20℃ for six months from June till December. Then the fronds were smashed to obtain the isolated vegetative cells, which could grow into normal frond seither in the laboratory or in natural sea waters.Results of the experiments revealed tb.at the survival rats of isolated cells is directly related to the water content of the fronds before freezing. When the water content 50% the survival rate was highest in this experiment.It seems possible by appling this principle produce great amount of seedlings to meet commercial need.