The aim of this research was to investigate the influence of konjac flour and/or soy proteinisolate on physicochemical and pasting properties of selected native starches (wheat, rice andglutinuous rice starch). Addition of konjac flour (0.5% and 1%) and/or soy protein isolate (5% and10%) increased (p  0.05) water absorption index, water solubility index, swelling power andsolubility of all starch pastes but decreased (p  0.05) their gel strength. The increased yellownessand apparent viscosity were given by mixed starch / konjac flour / soy protein isolate system. Thepresence of konjac flour and/or soy protein isolate affected the pasting properties of native starches.In case of wheat starch and rice starch, the konjac flour modified their peak viscosity and stabilitywhereas addition of of konjac flour and/or soy protein isolate decreased peak viscosity and stability.On contrary, glutinous rice starch /konjac flour system displayed lowered value of peak viscositywhereas the presence of konjac flour and/or soy protein isolate increased peak viscosity.The effect of mixed wheat starch /konjac flour / soy protein isolate on quality characteristics ofreduced-fat chiffon cakes were studied. All reduced-fat chiffon cakes had proximate composition,physical properties and sensory attributes differed (p  0.05) in relation to the control. The ratio ofmixed wheat starch /konjac flour / soy protein isolate at 89.5:0.5:10 was optimum for producing areduced-fat chiffon cake prepared with 50% replacement of vegetable oil with water.