2,4-Diamino-6-aryl-1,3,5-triazines were synthesized by using a solid-supported approach in which monoarylsubstituted triazines were captured directly from the crude reaction mixture by resin-bound amines. The effects of the synthesized compounds on inhibition activities against tumor cell lines (PC-3, K562, A549, and HO8910) were examined. Most of the obtained compounds demonstrated remarkable antiproliferative activities against K562, PC-3, and HO8910 cell lines. Particularly, compounds 8c exhibited prominent inhibition activity with IC(50) values of 1.01, 2.23, and 1.06 microM, respectively. The structure-activity relationships of 2,4-diamino-6-aryl-1,3,5-triazines are also discussed.