For a boundary layer above the porous surface at a given temperature of main flow and injected gas, the wall heat flux q(w), depends on the injection intensity in nonmonotonius way. The heat flux first increases with the growth in injection rate j(w), then after reaching a maximum it starts decreasing and tends to zero at j(w),-> j(er). The similarity problem between heat and mass transfer is considered for boundary layers with variable content. The effect of the Lewis number Le oil similarity conditions was demonstrated. In general case, the similarity ratio is a function not only Lewis number, but also the enthalpy difference. The common formula for description of similarity St(T)Le '' = St(D) "works" only for specific cases. Results oil the influence of flow acceleration and turbulence degree Tu oil characteristics of a boundary layer with combustion are presented. (c) 2005 Elsevier Ltd. All rights reserved.