We report transport studies on high-quality CeRu 4 Sb 1 2 single crystals. At temperatures below ~3K, both the electrical resistivity and thermoelectric power exhibit apparent anomalies correlated with a non-Fermi-liquid ground state. We succeeded in observing Shubnikov-de Haas oscillations both in the magnetoresistance and Hall effect. The result along with the Hall effect suggests a small semi-metallic Fermi surface (FS) made of highly correlated electrons in contrast with the large FS for LaRu 4 Sb 1 2 .