Phase-contrast x-ray imaging has been studied for materials, biological and medical sciences at the Hyogo-prefectural beamline (BL24XU) of the SPring-8. Its optical system consists of a successive arrangement of horizontal and vertical (+, −) silicon double crystals taking asymmetric Bragg reflection. A living insect and a frog were observed in real time at the photon energy of 15 keV. Boundary structures in samples were clearly observed with much higher contrast than those obtained in absorption-contrast imaging. The beamline BL24XU, optical system and experimental results are described.