Objective: Umbelliprenin is a prenylated compound, which belongs to the class of sesquiterpene coumarins. Umbelliprenin is synthesized by various Ferula species plants used for food preparation or consumed as food such as Citrus Limon. Recently, umbelliprenin has been attracted much attention for its strong antitumor activities. Lung cancer is one of the most common causes of cancer related deaths in both men and women in most of countries. It is among the 10 most frequent cancers in Iranian population. Materials and Methods: To measure cell cytotoxity of umbelliprenin on human lung cancer cell lines including A549 and QU-DB, and murine lung cancer carcinoma LLC1, MTT cytotoxicity assay was performed. Results: IC 50 values for QU-DB, A549, and LLC1 were: (34.5 ± 5.9), (47 ± 5.2), and (47± 3.1) µM respectively, using MTT assay. Data represent the mean ± SD of at least two independent experiments done in triplicate. Conclusion: We found that umbelliprenin acts as an anti cancer compound in lung cancer cell lines in both human and mice cell lines, but their molecular targets are not clear. Characterizations of molecular targets of umbelliprenin using proteomics techniques are underway.