The heat consumption of the conventional brick and concrete kilns is quite high and there is a great potential of energy saving. It was proved in practice that equiped with polyurethane foam layers and air tight doors, thermal insulation of the kilns can be remarkably improved. The heat lose of the dryer chamber and the total energy consumption were reduced by 60% and 12% respectively. The feasiability of using oil as an intermediate of heat transfer for energy saving also was dicussed.