Five new Diels-Alder type adducts, mongolicins A - E (1 - 5), and nine known compounds, mongolicin F (6), chalcomoracin (7), mulberrofuran T (8), mulberrofuran G (9), mulberrofuran F (10), albanol B (11), kuwanon O (12), mulberrofuran H (13) and kuwanon H (14), were isolated from the stem and root bark of Morus mongolica. Their structures were determined by spectroscopic analysis and chiroptical methods. Among them, compounds 3 and 5 showed potent anti-inflammatory activities (inhibition of release of β-glucuronidase from rat PMNs induced by PAF) with inhibitory ratios of 80.4 % (P < 0.05) and 77.0 % (P < 0.001) at a concentration of 10-5 mol L-1. Compounds 2, 6 and 12 were active as antioxidatives (inhibition of liver microsomal lipid peroxidation induced by Fe2+-Cys system) with inhibitory ratios of 83.6 % (P < 0.05), 86.0 % (P < 0.05), and 63.0 % (P < 0.05) at a concentration of 10-5 mol L-1.