A series of 1,4-phenylene-bis-chalcones 3a-3h were synthesized by the reaction of terephthalaldehyde with substituted arylketones in this study. The novel 1,4-phenylene-bis-pyrimidine-2-amine derivatives 5a-5h were obtained by the addition of guanidine hydrochloride to 1,4-phenylene-bis-chalcone 3a-3h in ethanolic KOH under reflux conditions.The structure of the compounds was explained by means of IR, 1 H NMR, 13 C NMR, and elemental analyses. The anticancer activities of 3a-3h and 5a-5h were investigated against rat brain tumor cells and human uterus carcinoma in vitro . Activity tests were performed as dose-dependent assays at eight concentrations. The positive control was 5fluorouracil (5-FU). Compounds 3c and 3d were examined and they showed high activities as compared to 5-FU against C6 (rat brain tumor) and HeLa (human uterus carcinoma) cells. The anticancer activity of 5h was better than that of 5-FU at high concentrations cell-selectively against C6 cells.