A pigment of Al2O3-CoO system has been prepared as a new green pigment for camouflage materials. The effect of the CoO content in the original mixture on the spectral reflectance of the pigment has been evaluated. The temperature condition of the pigment synthesis has been found. The pigment of Al2O3-CoO system has been modified as green camouflage pigment by ferric oxide, and the camouflage effect has also been estimated. The result shows that the pigment based on Al2O3-CoO system, as a substitute of Cr2O3, is a successful camouflage pigment.