Room- and variable-temperature photoluminescence from 3C-SiC aloetic-shaped nanowires was presented. The SiC nanowires were prepared on Si(100) substrates by the reaction of methane with silicon dioxide. Scanning electron microscope (SEM) and X-ray diffraction (XRD) are used to characterization the nanowires. A green photoluminescence (PL) band centered at 2.34 eV is observed in the nanowires at room temperature. The results from variable-temperature photoluminescence show anomalous temperature dependencies of the spectral characteristics. The emission intensity increases with decreasing temperature until reaching an intensity maximum at about 155 K, then it decreases at lower temperatures. The emission energy has little shift following temperature variations. The anomalous temperature dependencies of PL results may be explained by quantum confinement effect and phonon participation in the emission process.