A comprehensive analytical model has been developed to describe the structure of dust detonatins which simultaneously computes both the ipduction and reaction zones. Heterogeneous reactions which occur on the external particle surface and on the surface of pores within the particle are used to model the chemistry. The overall reaction rate in the induction zone is controlled by the heterogencous surface reaction rate while in the induction xone is controled by the heterogeneous surface reactio rate while in the reaction zone diffusion of the gas into the pores is found to be the rate limiting step. Conduction heat transfer within the particle, convective heat transfer between the particles and the gas and chemical heat release within the particles are considered in this model to describe the temperature distribution witin the psrticles in both the induction and reaction xones. Thermal runaway is used as the criterion of igoition at the end of the induction zone and the singularity at the C-J plane is used to terminate the reaction zone. Thernalrunaway is used as the criterion of ignition at the end of the induction a lack of sufficient data, some contants used in this model were chosen to provide the best fit between the theory and experiment. The model made it possible to compute the structure of dust detonations without separate treatment of the induction and reaction zones and was used to determine the effects of particle size on detonation structure and propagation velocity. In those cases in which experimental data was available computed and measured results were in good agreement.