Partial substitution of wheat or rice starches with konjac flour (0, 0.5 and 1%) and soy protein isolate (SPI) (0, 5 and 10%) was carried out to determine their influences on freezethaw stability. The addition of konjac flour incorporated with SPI resulted in lower separated water or syneresis of native wheat and rice starches. The highest freezethaw stability of wheat starch was obtained by adding 0.5% konjac flour and 5% SPI on each freezethaw cycle throughout 4 cycles (1 cycle = 18 h storage at 20± 2°C followed by 6 h storage at 29 ± 2°C), while that with 0.5% konjac flour and 10% SPI was optimal for rice starch. The separated water reduction in both starches was decreased with increasing of freezethawcycles, and the higher reduction was observed in wheat than rice starches on every each cycle.