Rice flours were treated using a thermostable 4-${alpha}$-glucanotransferase (GTase) from Thermus aquaticus for 1, 3, and 48 h. Molecular weight of modified rice starch rapidly decreased within 1 h of reaction, then slowed down. As the reaction proceeded, the proportions of short (<DP 11) and long (>DP 30) branched chains of modified starch increased, whereas the proportion of medium chains decreased. Rice cakes were prepared with native and GTase-treated rice flours (substitution at 5%) and kept for 3 and 21 h. Texture profile analysis indicated significantly increased hardness, adhesiveness, chewiness, and resilience in rice cakes containing treated rice flours. Sensory analysis revealed that the rice cakes containing 48 h-treated flour had significantly increased springiness, hardness, toughness, and adhesiveness during both storage periods. Meanwhile, it displayed the lowest starch-like attribute and crumbliness. These results suggested that the substitution for 48 h GTase-treated rice flour could retard the retrogradation of rice cakes.