Abstract: Under some certain assumptions, the physical model of the air combustion system was simplified to a laminar flume system. The mathematical model of the laminar flame system, which was built according to thermodynamics theory and the corresponding conservative laws, was studied. With the aid of qualitative theory and method of ordinary differential equations, the location of singular points on the Rayleigh curves is determined, the qualitative structure and the stability of the singular points of the laminar flame system, which are located in the areas of deflagration and detonation, are given for different
parameter values and uses of combustion. The phase portraits of the laminar flame system in the reaction-stagnation enthalpy and combustion velocity-stagnation enthalpy planes are shown in the corresponding figures.

Key words: laminar flame system, Rayleigh curve, singular point, orbit, phase portrait, nonlinear;dynamic system;bifurcation