Five aristolochic lactam alkaloids (1-5), including two new ones (1-2), along with two new natural products (6- 7) were isolated from Piper macropodum. The structures of the new compounds (1-2) were elucidated by extensive spectroscopic analysis. The structures of compounds (3-7) were identified on the basis of NMR spectroscopic data analyses and comparison with the data reported in literature. Consequently, compounds 1-5 showed good inhibitory effects on NO releasing from RAW264.7 cells induced by LPS.