My research subjects are Improvement of cryogenic stability and enhancement of magnetic field of large superconducting magnets. Specific research subjects are (1) application of react-and-wind method to a A15 superconducting conductor, (2) mechanical characteristics and cryogenic stability of large superconducting conductors, (3) an analysis of cryogenic stability of the LHD helical coil, (4) a conceptual design of a superconducting magnet for fusion reactors, and so on.