This paper presents an experimental study on the energy saving effect of reflective coatings on exterior walls. Two identical test buildings were built in Zhejiang College of Construction, one of which is covered with reflective coatings and the other not. The wall temperature fluctuation of both buildings is monitored in summer, which includes the east, south and west walls. The results indicate that the maximum reduction of wall temperature is 9-10 °C in the building with reflective coatings, compared with wall temperature in the other without it. The reduction in heat gain of east, south and west walls is obvious, so is the cooling effect. The reduction in electricity consumption of air-conditioning system in the building with reflective coatings is 0.94 KWh/m2 per month times by calculation, which well proves the energy saving effect of reflective coatings.