Abstract: Using two-dimensional quasi-geostrophic and semi-geostrophic models, processes of disturbance generation forced by baroclinic current overflowing north-south mountain ridge are studied. It is found that the disturbance excited by topographic effects predominates the early stage of the development with the scale of the disturbance comparable with the width of the topograph, while the later stage witnesses major roles of baroclinic instability with the scale of the disturbance comparable with the unstable baroclinic waves. The ending part of the study focuses on comparison between the two models and discussion of the implication of the results achieved in real atmospheric processes.