Two New alkaloids, 1-(1-hydroxy-2-methoxy)ethyl-4-methoxy- β-carboline (IV) and 5hydroxymethylcanthin-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.