Abstract: Using a quasi-geostrophic three layer baroclinic model, the baroclinic instability in different vertical stratification of temperature and in different vertical wind shear conditions are discussed and analysed. It is found that not only the stratification of atmosphere defines the critical wavelength of instable waves, but also its vertical difference determines the contribution to The baroclinic instability (in each level) the baroclinic development of small perturbations depends primarily on thermal and dynamical conditions in layers with smaller static stability. It is also found that the wind is stronger in high and low levels, it is. most favourable in the develepment of instable disturbances.