Abstract: The noble metal Pt modified WO₃（ Pt/WO₃） was prepared by microwave assisted solvothermal method in one pot,and the material was applied to the detection of breath biomarker of acetone. The experimental results show that the precious metal Pt modified WO₃ significantly improves the sensitivity of pure WO₃. The sample of Pt/WO₃-2 which 0.25 mL 0.1 mol L^-1 H₂PtCl₆ ethanol solution was added to reaction solution shows the highest sensitivity towards acetone. The sensitivity of Pt/WO₃-2 is 23 folds higher than pure WO₃. The detection limit of acetone is as low as 250 ppm. The sample of Pt/WO₃-2 exhibits good selectivity and long-term stability towards acetone. The method of microwave assisted solvothermal in one pot which we took to synthesis noble metal modified metal oxide provide a new strategy to fabrication high sensitivity gas sensors.