The occurrence of new bufotoxins, in which L-histidine, L-3-methylhistidine, or L-1methylhistidine replaces the arginine residue of hitherto known "bufotoxin," in the skin of the Formosan toad, Bufo melanostictus SCHNEIDER, is reported. Five novel bufotoxins, bufotalin 3suberoyl-L-histidine, -3-methylhistidine and -1-methylhistidine esters and 19-hydroxybufalin 3suberovl-L-histidine and -3-methylhistidine esters, were separated by usual chromatographic methods including reversed phase high-performance liquid chromatography, and their structures were elucidated by degradative and synthetic means.