The Program SUBMODELS [1] is aimed to exhaust all possibilities derived from the symmetry of differential equations for construction of submodels (i.e., systems of equations of the reduced dimension) which describe classes of exact solutions for initial equations. In the frame of this Program, our paper communicates the description of all (up to similarity) regular submodels for the system of Gas Dynamics with the general state equation. Submodels are classified by their types (σ, δ), whereσis a rank andδis a defect. Regularity of a submodel means that invariant independent variables are functions of initial independent variables only. The classification tables, comments to them, and some characteristic examples are presented.