Dibenzylideneacetone (DBA), an analogue of curcumin has been shown to have anti-cancer activity in a variety of tumor cell lines. However, the anti-cancer activity of DBA and its molecular mechanism in HN22 oral cancer cell line have not been fully explored. The effects of DBA on anti-proliferative and apoptotic activity were evaluated by the trypan blue exclusion assay, 4’-6-diamidino-2-phenylindole (DAPI) staining, Western blot analysis, and reverse transcriptase-polymerase chain Reaction (RT-PCR). Our data showed that the treatment of DBA to HN22 cells exerted anti-proliferative and apoptotic activities and the activity was accompanied by a decrease in Sp1 protein, Sp1 mRNA and its promoter activity. DBA also reduced the expression level of Sp1 protein and caused apoptotic cell death in HN22 cells simultaneouly. Phosphorylation of ERK and JNK were regulated by DBA whereas phosphorylation of p38 was not altered. Overall, our results suggest that the regulation of Sp1 activities and ERK/JNK are involved in DBA-induced apoptosis and DBA can be a promising anticancer drug candidate for the treatment of oral cancer.