Here, we present the final technical report on AFOSR Grant F49620-93-0064, Studies Of Hypersonic Boundary Layer Behavior. The grant covered three interrelated research efforts: a study of the structure of hypersonic turbulent boundary layers and shock wave boundary layer interactions, a study of boundary layer transition at supersonic and hypersonic speeds, and the development and application of new optical techniques including filtered Rayleigh scattering and RELIEF to obtain multi-dimensional velocity and density data in the supersonic and hypersonic regimes. The research was performed using the existing facilities in the Applied Physics and Lasers Laboratory and at the Princeton University Gas Dynamics Laboratory. The construction of a new boundary layer facility was also partly supported under this contract. The new facility is designed to operate at Mach numbers from 2 to 8, with a range of Reynolds numbers so that the boundary layer can be laminar or turbulent, at all Mach numbers. It is primarily designed to operate with air (and possibly other gases including nitrogen and SF6) to exploit the new optical techniques and to help isolate specific Mach number and Reynolds number effects. It will be ready for its first trials in May, 1995. (AN).