The flotation spectrophotometric method for the determination of platinum with isochromatic dye ion-pair is described. Rhodamine 6G (R6G) was produced and entered into aqueous phase when pH = 5.5 buffer solution was added to the Pt (SnCl3)5 (R6G)3 by isopropyl ether flotation. And then R6G. TBF was floated by tetrabromofluorescein(TBF)with toluene. The floatation was dissolved in acetone and absorbance of the solution was measured at 530nm. The sensitivity was raised because of the six dyes (Pt : R6G : TBF = 1 : 3 : 3) assistant effect. The molar absorptivity of this method is 5.92 x 10(5)L x mol(-1) x cm(-1). Beer's law was obeyed in the range of 0-2 microg/10mL with a relative standard deviation of 3.8%. The method was applied satisfactorily to the determination of platinum contained in catalysts without separation.