Two New alkaloids, 1-(1-hydroxy-2-methoxy) ethyl-4-methoxy-β-carboline (IV) and 5-hydroxymethylcanthin-6-one (V), have been isolated from the root bark of Ailanthus altissima SWINGLE (Simaroubaceae) together with three known alkaloids, β-carboline-1-propionic acid (I), 1-carbamoyl-β-carboline (II), and 1-carbomethoxy-β-carboline (III). The structures were elucidated on the basis of spectral and chemical evidence.