The inhibitory effect of omega-3 such as linolenic acid (LNA), docosahexaenoic acid (DNA) and eicosapentaenoic acid(EPA) on the growth of normal cell lines and cancer cell lines was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyItetrazolium bromide (MTT) and 2,3-bis-2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-caboxanilide (XTT) methods. LNA was found to decrease the cell viability of human oral epithelioid carcinoma cells (KB) in the MTT assay, whereas EPA appeared to inhibit the cell adhesion activity of human skin melanoma cells (SK-MEL-3) in the XTT assay analysis. DPPH radical scavenging activity was examined on LNA, DHA and EPA at the concentration of 100 ${mu}M$, where they showed about 53% scavenging activity. These results suggest that omega-3 unsaturated fatty acid has a potential anticancer activity.