CrN/AlSiN multilayer coatings with bilayer period (Λ) between 2.3 nm and 8.0 nm were synthesized from Cr and AlSi (Si=20 and 66 at.%) targets by using a closed-field unbalanced magnetron sputtering (CFUBMS) and their crystal structure, chemical composition and mechanical properties have been investigated by glow discharge optical emission spectroscopy (GDOES), Xray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and nano-indenter. In order to evaluate the thermal stability of the coatings annealing treatments for 30 min at temperature between 800 °C and 1000 °C were performed in air. The thermal stability of the CrN/AlSiN multilayer coatings was improved with increasing Si content. In case of the coating with Si content of 18.2 at.%, a superior thermal stability was exhibited even after annealed at 1000 °C and the relatively high hardness of 25 GPa was maintained without a significant decrease in hardness. The reduced oxidation rate of the coatings at high temperature could be attributed to the formation of the amorphous Si3N4 phase around the crystalline AlN phase.