In order to identify effective amino acid species, survival and growth of Neopyropia yezoensis protoplasts cultured using 18 amino acids were examined. Survival rates of each protoplast cultured for 1 week with arginine, asparagine, ornithine and tyrosine were similar to that of the control condition. Other amino acids significantly reduced the survival rates than the control. Growth of each protoplast cultured for 2 weeks with β-alanine, arginine, glutamine, histidine, lysine, ornithine and phenylalanine were significantly higher than that of the control. Histidine might be useful to make only thallus grow, although survival rate was very low. Arginine and ornithine had potentials to be able to promote the growth without negative influences on the survivals of nori cells.