Spectral selective radiating materials (SSRMs) are attractive because Df their applicability to passive cooling with no external energy consumption. SSRMs can be cooled by IR emission in the spectral region at 8 and 13 mu m of the atmospheric window. We have designed a new SSRM which consists of an SiO film as outer layer, V1-xWxO2 thermochromic (TC) film as intermediate layer and blackbody as the substrate respectively. In this study, the radiative cooling powers of the SSRM were simulated using the refractive indexes of SiO and V1-xWxO2 obtained separately by optical measurements. The results revealed that the newly designed SSRM can attain a stable surface temperature that can be controlled by varying the value of x in V1-xWxO2. In this manner the transition temperature from metal to semiconductor states can be controlled by altering the value of x.