The absorptance of AlN-Al(absorbing coating)/Al solar spectrum(0.34 similar to 1.5 mu m) selective absorbing surface, containing 8-layer AIN-AI composite materials and with distinctive or non-boundaries between the layers, deposited by sputtering technology and heat-treated at 400 degrees C(60min) is about 0.95 and its thermal emittance is close to 0.07 similar to 0.08(80 degrees C)But on the condition that the absorptance is unchanged the thermal emittance dropped to 0.04 for the AlN-Al coating composed of mater volum fractionic 0.42. 0.25 and 0.00 films