Indium (III) complex with Alizarin [1,2-Dihydroxyanthraquinone] have been investigated polarographically using Potassium Nitrate as supporting electrolyte in aqueous non-aqueous medium at 293 K and 303 K and pH 6.0 to 6.4. Indium (III) formed 1:1, 1:2 and 1:3 complex species in solution with Alizarin. DeFord and Hume?s method and Mihailove?s method have been applied for the determination of stability constants and kinetic parameters were evaluated for the reduction process at d.m.e. The stability constant of In (III) complexes with Alizarin at 303 K are 1.5502, 1.9701 and 4.4800 and by using Mihailov?s method are 1.4823, 2.9744 and 4.2904.