The structure and electronic properties of Cs3C60 under ambient pressure were studied by X-ray diffraction (XRD) and ESR. The XRD showed that Cs3C60 takes a body-centered orthorhombic structure as the main phase. No clear structural change was observed down to 9 K. The temperature dependence of the ESR peak suggested that Cs3C60 exhibits a metallic behavior but no metal-insulator transition down to 1.9 K, contrary to a previous prediction. (C) 1998 Elsevier Science B.V. All rights reserved.