In order to investigate the effects of phenylalanine, tyrosine and tyramine on the growth of Lycoris radiata suspension cells and the accumulation of alkaloids, the growth quantity of the cells as well as the content of alkaloids in cells were determined, which were treated with above three kinds of precursors alone and phenylalanine combined with tyrosine respectively. The results indicate that the addition of phenylalanine alone and addition of phenylalanine on the basis of tyrosine at high concentration(...