Metal-metal oxide (M-M oxide) cermet solar selective coatings with a double cermet layer film structure were deposited on the Al-deposited glass substrate by using a directed current (DC) magnetron sputtering technology. M oxide (CrO and ZrO) was used as the ceramic component in the cermets, and Cr and Zr used as the metallic components. In addition, black Cr (Cr-$Cr_2O_3$ cermet) solar selective coatings were deposited on the Ni-plated Cu substrate by using a electroplating method for comparison. The thermal stability tests were carried out for performance evaluation of solar coatings. Reflectance measurements were used to evaluate both solar absorptance(${alpha}$) and thermal emittance (${epsilon}$) of the solar coatings before and after thermal testing by using a spectrometer. Optical properties of optimized cermet solar coatings were ${alpha}{simeq}0.94-0.96$ and ${epsilon}{simeq}0.1$ ($100^{circ}C$). The results of thermal stability test of M-M oxide solar coatings showed that the Cr-CrO cermet solar selective coatings were more stable than the Zr-ZrO cermet selective coatings at temperature of both $400^{circ}C$ in air and $450^{circ}C$ in vacuum. The black Cr solar selective coatings were degraded in air at temperature of $400^{circ}C$. The main optical degradation modes of these coatings were diffusion of metal atoms, and oxidation.