Rice starch (RS) and soybean flour (S) were mixed in different proportions， and the mixed system was analyzed for pasting characteristics， particle characteristics， rheology and tribological properties. S inhibited starch pasting， leading to an increase in the pasting temperature. As the concentration of S increased， the pasting temperature of the mixtures increased from 85.55 ℃ to 94.5 ℃， the peak viscosity decreased from 1 461 cp to 25 cp， the decay value from 741 cp to 2 cp， and the regrowth value from 1 028 cp to 13 cp. And the particle size increased after RS and S mixed pasting， which inhibited the formation of starch gel. All samples exhibited shear dilution behavior， and the addition of soybean flour produced lower viscosity， yield stress， and consistency coefficient. At a sliding speed of < 10 mm/s， the combination of RS and S increased the friction coefficient， except for RS/S 9/1.