Self-sustaining detonation along a combustible dust deposit on a bottom wall have been investigated experimentally and theoreticall. Experiments were conducted in a square cross-section tube. Three kinds of particles with a mean dianneter of 15μm were used; AL, RDX, and HMX. Sharp-shadow photographs were taken by means of a spectial optical system and shock-wave veloeties were measured by pressore transducers. It has been shown that the steady-state ditonation velocity is independent with initial shock wave strengths. An analytical model has been developed to describe the two-dimensional structure of dust-film detonations. A set of equations for the twe-phase turbulent-reaction boundary layer considering the particle ingestion and the interphase transfers and a general Chapman-Jouguet condition were derived. The Lees-Dorodnytzin transformation usually applied to the compressibie boundary layer has been extended to fit the two-phase reacting case, and the numerical siulations have been performed by applying a Box method and an improved particle source in cell (PSIC) method. Which shows that the structure of the boundary layer behind the shock fornt consists of an inducton zone, a reaction, and a diffusion zone. Computed and measured results are in reasonable agreement.