The CINC-1 is a member of rat interleukin-8 with chemotactic and activating properties to neutrophils. The CINC-1 induction in LPS-stimulated rat peritoneal macrophages was analyzed using a sensitive enzyme-linked immunosorbent assay. The peritoneal macrophages contained about 3 ng/ml as a basal level, and induced to maximal 18 ng/ml of CINC-1 by stimulation with 5 ${mu}g/ml$ of LPS. Antiinflammatory steroids of dexamethasone and triamcinolon significantly suppressed the CINC-1 induction, where as aspirin and idomethacin did not show suppression. Inhibitory effects on the CINC-1 induction by natural triterpenoids having steroidal structures were analyzed. Among the 39 kinds of triterpenoids isolated from herbal medicines, acacigenin B and nigaichigoside F1 exhibited the highest suppression on the CINC-1 induction.