The N-(m-methylphenyl)-N＇-(sodium p-aminobenzenesulfonate)-thiourea (MMT) was good reagent of water solu-bility. In the medium of an HAc-NaAc buffer solution and hexadecyltrimethylammonium bromide (CTMAB), MMPT can react with platinum (Ⅳ) and palladium ( Ⅱ ) to form green and brown soluble complex. The maximum absorbance of the complex was at λ^Ptmax=754. 4nm and,λ^Ptmax=304.6 Beer＇s law was obeyed with the concentration in the range of 0-32.0μg Pt(Ⅳ)/25 mLand 0-25.0μg Pd( Ⅱ )/25 mL for platinum (Ⅳ) and palladium( Ⅱ ) respectively. The correlated coefficient was r754.4=0. 999 5 for platinum (Ⅳ) ; and r304, 6 = 0. 999 9 for palladium ( Ⅱ ). Their molar absorption coefficients were ε^Pd304.6=7.4×10^4L·mol^-1·cm^-1 and ε^Pd304.6=7.4×10^4 L·mol^-1·cm^-1 respectively. The contents of platinum (Ⅳ) and palladium (Ⅱ) were converted by determination of the absorbency of mix solution of platinum (Ⅳ) and palladium ( Ⅱ) at 754.4 and 304. 6 nm. Only Cu^2+ and Co^2+ interfered with the determination of palladium ( Ⅱ ) among 50 coexistent ions, so the selectivity was good. It can be used for the determination of content of synthesis samples. The relative standard deviation (RSD) was less than 2.0%, and the recovery(%) was in the range of 96 %-104 %. The results are satisfactory. Because the reagent reacts with platinum (Ⅳ) and palladium ( Ⅱ) to form water soluble complex and does not require pre-separation for simultaneous determination of platinum (Ⅳ) and palladium ( Ⅱ ), the method is easy to operate, rapid and environment-friendly.