A new cytokinin has been isolated from the culture filtrate of Pseudomonas amygdali together with isopentenyladenine, dihydrozeatin and trans-zeatin. The structure of the new cytokinin was assigned on the basis of spectroscopic data and by its partial synthesis starting from the trans-zeatin and the 2-deoxy-D-ribose. It was identified as the 6-(4-hydroxy-3-methylbut-trans-2-enylamino)-9- β -2'-deoxy-D-ribofuranosylpurine