In bioassay-guided search for inducible nitric oxide synthase (iNOS) inhibitory compounds from higher plants of South Korea, two $eta$-carboline (2) have been isolated form the cortex of Melia azedarach var. japonica. The structures of these compounds were elucidated on the basis of spectroscopic data. Compounds 1 to 2 showed marked inhibitory activity of iNOS on LPS-and interferon-${gamma}$-stimulated RAW 264.7 cells.