A new hypersonic inlet named three-dimensional section controllable internal waverider inlet is presented in this paper to achieve the goal of section shape geometric transition and complete capture of the upstream mass. On the basis of the association between hypersonic waverider airframe and streamtraced hypersonic inlet, the waverider concept is extended to yield results for the internal flows, namely internal waverider concept. It is proven theoretically that not osculating cones but osculating axisymmetric theory is appropriate for the design of section controllable internal waverider inlet. And two design methods out of the internal waverider concept are proposed subsequently to construct two inlets with specific section shape request, triangle to ellipse and rectangle to ellipse ones. The calculation results show that the inlets are capable of keeping their shock structures and the main flow characteristics exactly as their derived flowfield. Further, the inlets successfully capture all the upstream mass despite their complicated cross-section transitions. It is believed that the concept proposed explores a new way of designing three-dimensional hypersonic inlets with special demand of section shape transition. However, the detailed flow characteristic and the performance of the internal waverider inlets are still under investigation. section controllable, internal waverider, hypersonic inlet, osculating flow, all mass captureThe new design concept of inward turning hypersonic inlet [1] has received considerable attention in the research community of hypersonic inlet design. It has been proven lately that the inlet holds the potential of better aerodynamic performance than those with conventional compression styles. For example, the JAWS [2,3] developed by U.S. Air Force Research Laboratory (AFRL) got a 24.87% net thrust addition compared with a typical two-dimensional planar hypersonic inlet. In June 2007, the hypersonic collaborative Australia/United States experiment (HyCAUSE) [4,5] flight experimental scramjet engine validated the performance of another three-dimensional inward turning hypersonic inlet. Recently, Lockheed has announced that their next generation hypersonic aircraft, Force Application and Launch from CONUS (FALCON) [6,7] , will also contain two modules of the innovative three-dimensional inward turning inlet. In the critical reviews [8][9][10] , Billig from Johns Hopkins University, stated the foundation of the concept, detailed design method as well as the performance of streamtraced inlet, an important member of the inward turning inlets. More significantly, it is believed [10] that the threedimensional inward turning inlet will lead the hypersonic inlet research in the future and consequently bring about a revolution in scramjet propulsion technology.The ongoing three-dimensional hypersonic inlets include Busemann, JAWS, modular waverider, rectangular to elliptical shape transition (REST) and rectangular to circular shape transition (RCST) ones. According to their integration manner...