We examined whether indomethacin, noscapine, coumarin, uridine and betaine affect airway mucin production induced by EGF or TNF-${alpha}$ from NCI-H292 cells. Cells were pretreated with each agent for 30 min and then stimulated with EGF or TNF-${alpha}$ for 24 h. Of the five compounds, coumarin suppressed airway mucin production induced by EGF or TNF-${alpha}$. However, indomethacin suppressed airway mucin production induced by EGF. This result suggests that coumarin and indomethacin can regulate the production of mucin induced by EGF, by directly acting on airway epithelial cells.