摘要： We conducted near-infrared (JHK s) imaging polarimetry toward the infrared dark cloud (IRDC) M 17 SWex, including almost all of the IRDC ?laments as well as its outskirts, with the polarimeter SIRPOL on the IRSF 1.4 m telescope. We revealed the magnetic ?elds of M 17 SWex with our polarization-detected sources that were selected by some criteria based on their near-IR colors and the column densities toward them, which were derived from the Herschel data. The selected sources indicate not only that the ordered magnetic ?eld is perpendicular to the cloud elongation as a whole, but also that at both ends of the elongated cloud the magnetic ?eld appears to be bent toward its central part, i.e., a large-scale hourglass-shaped magnetic ?eld perpendicular to the cloud elongation. In addition to this general trend, the elongations of the ?lamentary subregions within the dense parts of the cloud appear to be mostly perpendicular to their local magnetic ?elds, while the magnetic ?elds of the outskirts appear to follow the thin ?laments that protrude from the dense parts. The magnetic strengths were estimated to be ～70–300 μG in the subregions, of which the lengths and average number densities are ～3–9 pc and ～2–7 × 103 cm?3, respectively, by the Davis–Chandrasekhar–Fermi method with the angular dispersion of our polarization data and the velocity dispersion derived from the C18O (J = 1–0) data obtained by the Nobeyama 45 m telescope. These ?eld con?gurations and our magnetic stability analysis of the subregions imply that the magnetic ?eld has controlled the formation/evolution of the M 17 SWex cloud.