Detailed gas movements ahead of propagating flames through layered flammable mixtures have been theoretically simulated on the basis of convenient models. In the analysis, two-dimensional inviscid flow fields and constant flame velocities during propagation are assumed. Thermal expansion of gas due to combustion at the flame front is replaced by an imaginary source behind the flame front. Two cases are analyzed. In one case, a flat, flammable mixture layer, through which a flame propagates, is assumed to be established in an open space, and in the other case, it is assumed to be established in contact with a liquid or solid surface parallel to the layer. Equations representing the flow fields, fuel concentration distributions, gas particle paths, and flame front shapes are derived. The theoretical results obtained in the present study are shown to agree fairly well with the experimental results presented in previous reports.