In this paper, recent studies about a hypersonic air intake (inlet) for space planes conducted at Japan Aerospace Exploration Agency (JAXA)/the Institute of Space Technology and Aeronautics (ISTA) are presented. For a hypersonic air intake that is used from lift-off to Mach 6, such as an intake of ATREX engine, both aerodynamic performance and weight are important parameters. As a candidate of the intake of the ATREX engine, both axisymmetric and rectangular (two-dimensional) intakes are studied numerically and experimentally. An effect of the intake throat Reynolds number and an effect of spike tip oblique shock incidents on the cowl inside are investigated by wind tunnel tests of the axisymmetric intake. An effectiveness of a new concept intake that is Multi Row Disk intake is shown. Total pressure recovery and mass capture ratio of the rectangular intake is estimated by one-dimensional analysis and CFD. Structural analysis of flyable intake model whose main material is carbon-carbon composite is conducted. Finally, aerodynamic performance and structural weight of each intakes are compared.