After an introduction of heat convection problems by Oberbeck-Boussinesq equations, heat convection of compressible atmosphere is discussed in a horizontal strip domain heated from below under gravitation. The stability or instability of the heat conduction state is considered with respect to Rayleigh-Spiegel number. Taking into account their incompressible limit to the Oberbeck-Boussinesq system, stationary bifurcations ( pattern formations ) are obtained from the heat conduction state as the Rayleigh-Spiegel number increases across the critical value.