Ten sesquiterpenoids (1-10) and six phenylpropanoid derivatives (11-16) were isolated from the flower buds of Magnolia biondii Pamp. Their structures were determined by 1D- and 2D-NMR spectroscopy, mass spectrometry, and optical rotation. To evaluate their anti-allergic properties, the inhibitory effect of each isolate (1-16) on interleukin-2 (IL-2) gene expression was examined in Jurkat T cells. Among the isolated compounds, three sesquiterpenoids (2, 5, and 7) and two monoterpenoids (12 and 13) strongly inhibited IL-2 production in Jurkat T cells. Four compounds, (-)-parthenolide (2), eudesm-4(15)-eno-1β,6α-diol (5), biondinin D (12), and tiliroside (16), showed cytotoxicity against Jurkat T cells. In addition, (-)-parthenolide (2) exhibited cytotoxicity against the human cervical cancer HeLa cell line, the human breast cancer MCF-7, and human promyelocytic leukemia HL-60 cell lines.