Abstract: The second part of the present study investigates instability of a baroclinic basic flow against the transversal mesoscale disturbances. By generalizing the Eady model to an ageostrophic one, the bi-mode and even mufti-mode instability spectra may occur for a baroclinic basic flow. The Eady-mode appears at synoptic scales, whereas the ageostrophic, baroclinic mode appears at inertial scales ranging from sevenal tens to hundreds kinometers. The Eady-mode, with a qrasi-geostrophic structure, has a larger vertical depth, while the meso-modes are mostly confined to the middle and lower troposphere with an asymmetric "cat eyes" pattern in the vertical cross section and an alternative distribution of divergence and vorticity in the horizontal plane. The growth rate of the mesoscale mode is about four times larger than that of the Eady-mode for the same wind profile of linear distribution. the major energy source, which supports these two modes, is the baroclinic available potential energy stored in a rotating basic flow. The results of this paper may be useful in analysis of the mesoscale distur-bances'propagating along a basic flow.