Background : Amomum tsao-ko (Zingiberaceae) is widely distributed among several countries in Asia. It’s dried fruit is widely used in Korea for medical plant, China and Japan for the treatment of dyspepsia, eliminates, vomiting, abdominal pain, phlegm, warms the spleen, and malaria. In this study, we describe the structural determination of the new compounds and the inhibitory activities of isolated compounds against LPS-induced NO production in RAW264.7 cells. Methods and Results : The fruits of A. tsao-ko were extracted with 80% EtOH two times at room temperature. The EtOH extract was suspended in distilled water and partitioned with solvent to give CH2Cl2, EtOAc and n-BuOH. The CH2Cl2 was suspended in n-hexane and partitioned with solvent to give 50%, 70% and 90% MeOH. The purification of each fraction by column chromatography separation and HPLC analysis. Consequently, one new benzaldehyde (1) and two new cycloterpenals (2 and 3) along with five known compounds (4 –8) have been isolated from the fruits of A. tsao-ko. The structure and relative stereochemistry were determined from HRMS, 1D and extensive 2D NMR techniques as well as by comparison of their data with the published values. Conclusion : These compounds were identified as Amotsaokonal A (1), Amotsaokonal B (2), Amotsaokonal C (3), methyl linolenate (4), trans-nerolidol (5), (2E)-dodecenyl acetate (6), (2E)-dodecenyl acetate (7), and pyrrole-2-carboxylic acid (8). All isolates were tested for their inhibitory activities on LPS-induced nitric oxide production in RAW264.7 cells.