Highly active and stable carbon supported PtSnO2 catalyst with Pt:Sn ratio of 3:1 is prepared by a modified polyol method. The tin oxide is prepared via a facile co-precipitation method using stannic chloride solution and calcined at 500°C to form only tetragonal rutile structures of SnO2. The PtSnO2/C catalyst is synthesized through an ex situ method named as PtSnO2/C (E). The role of SnO2 and preparation method of PtSnO2 (E) to enhance the ECSA, for oxidation of ethanol, are considered and the activity is compared to synthesized in situ catalyst named PtSnO2 (I) method using SnCl2. The electro-catalysts are characterized using XRD, SEM-EDX, ICP-OES, TEM, Cyclic Voltammetry (CV), Choronoamperometry (CA), Electrochemical Impedance Spectroscopy (EIS) and direct alcohol fuel cell test (DAFC). The ethanol and acetaldehyde oxidation reaction activity of the catalyst are compared to PtSnO2/C (I) and Pt/C and ranked in order: PtSnO2 (E) > PtSnO2 (I) > Pt. It is found that the stability of PtSnO2/C (E) is considerably higher than that of PtSnO2/C (I) and Pt/C. The direct ethanol fuel cells (DEFCs) with PtSnO2/C (E) and PtSnO2/C (I) as modified electro-catalyst and Pt/C anode catalyst are also tested with ethanol and filled with acetaldehyde as a fuel. The synthesized catalyst shows higher open circuit voltage (OCV) and power density for ethanol and acetaldehyde compared with PtSnO2/C (I) and Pt/C as anode catalysts.