2-Arylchromones, also known as flavones, are among the most ubiquitous classes of natural products occurring in the plant kingdom. On the other hand, 2-styrylchromones are relatively scarce in nature and only a few compounds has been isolated from the blue-green algae species. Therefore, new 2-arylethenylchromone derivatives ( 4a∼n, 5a∼f) were synthesized by the aldol condensation of 2-methylchromone ( 3) with several aromatic aldehydes in order to evaluate their cytotoxicities using a MTT assay on three tumor cells. 2-Arylethenylchromone derivative 4a showed the significant cytotoxic activities on KB, HL-60 and P-388 cell lines with $IC_{50}$/ values of 25.2, 63.59 and 49.51 $mu$M, respectively, indicating that 2-arylethenylchromone skeleton has a potential anti-tumor application.