A series of isoxazol-indolin-2-one was designed for GSK-3${eta}$ inhibitors as novel anticancer agents based on their binding mode analysis in GSK-3${eta}$ crystal structure. Total 21 compounds were synthesized and evaluated for their inhibitory activity against two tumor cell lines (DU145 and HT29). Most of the synthesized compounds were potent with above 80% inhibitory activity at 100 ${mu}M$, and several compounds were examined for inhibitory activity against GSK-3${eta}$. Among them, 15(Z) ($R_1$=H, $R_2$=3-Cl-phenyl) was most active with 78% inhibition of tumor cell line (HT29) at 20 ${mu}M$ and 72% inhibition of GSK-3${eta}$ at 20 ${mu}M$.