The present study investigated the effect of water extract from the residue of jelly fig achenes (WERJFA) on the protection of DNA against hydroxyl radical damage and on the growth inhibition of three cancer cell lines, including mouse colon cancer CT-26, human hepatoma HepG2 and breast cancer MCF-7. DNA protection against hydroxyl radical from hydrogen peroxide was assayed by agarose gel electrophoresis. Growth inhibition of the cell lines was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that WERJFA was able to reduce the hydroxyl radical-induced DNA damage and to inhibit the growth of the three cancer cell lines with CT-26 being the most vulnerable one, HepG2 the second, while MCF-7 the least affected. The growth inhibition rates of WERJFA (200 μg total solids/mL) on CT-26 and HepG2 were 85.4% and 60.0%, respectively. MTT assay was also applied in the rat hepatocyte Clone 9 cytotoxicity test. No cytotoxicity of WERJFA (0-200 μg total solids/mL) was observed. These lines of evidence support that WERJFA has the potential to be an antitumor agent. Ultrafiltration enhanced the growth inhibitory effect of WERJFA. Among all the fractions of filtrate, the 3-10 kDa fraction had the highest inhibition on HepG2 cells, reaching 73.5% reduction of growth when added at 200 μg total solids/mL and incubated for 72 hr.