Abstract: Necessary conditions for baroclinic instability in multi-layer baroclinic atmosphere is derived with a multi-layer model and growth rates of unstable waves in real basic flows computed for all four seasons of the year using iteration-reduction method. The growth rate of long wave disturbance is found to be the largest and the wavelength of unstable wave the longest in winter, decreasing as it goes to spring and summer. Parameter 3 stabilizes unstable long waves by reducing its growth rate and wavelength range. Froude number acts in reverse with β, making long waves unstable. Topography tends to reduce the length range of unstable waves while having complex effects on the growth rates.