This article presents the results of laser ignition experiments on the model pressed composites 0.45Si + 0.55Pb/sub 3/O/sub 4/ and 0.25A1 + 0.75 KC1O/sub 4/ for various pulse lengths and pressing loads. The GOS-30M neodymium laser operated in the free running mode and the Q-switched mode. The specimens were ignited by the direct action of the lightly focused radiation. An analysis of the various possibilities of using radiant energy with the investigated compositions showed that the heating of the medium by a short laser pulse is essentially nonuniform owing to the difference in the optical and thermophysical characteristics of the components. A plane fuel particle with a characteristic dimension present in the surface layer under conditions of isotropic irradiation is considered. It is determined that the formation of an ignition center from one or more fuel particles takes place under conditions of competition between the heat supplied by the chemical reaction and the losses.