Thermal gasification of coal and bagasse dust in the products of detonation combustion of hydrogen-oxygen stoichiometric mixtures, with different argon dilution was investigated. The influence of initial pressure, dust concentration and argon dilution on the final pressure, gasification efficiency and gasification products and their composition during detonation process were studied. Experiments were performed in a high pressure detonation tube with initial pressure of the gaseous mixture varying in the range of 1-5 MPa. The Sinai coal and bagasse of different volatile content were used. After the experiments, the quantity of the gasification products and their composition, were determined. Usually the final pressure of gasification products was approximately 95%. of the initial pressure of hydrogen-oxygen mixture. The major products of gasification were: H2 and CO2, followed by CO2 and CH4. Heating value of the produced gas was usually 50% to 70% higher than that of the heat of combustion of hydrogen used for gasification. Kinetic constants of the gasification process were calculated with the assumption of the equilibrium temperature. The obtained kinetic data can be used for the calculation of high temperature gasification and also for calculations of the gasification reaction in flames.