The properties of large amplitude vortices were numerically investigated using a set of two-layer primitive equations. Numerical experiments are systematically conducted for the f and β planes, quasigeostrophic (small amplitude) and frontal-geostrophic (large amplitude) dynamics, cyclone and anticyclone, and vortex sizes comparable to the radius of deformation and larger. It is shown that the anticyclonic vortex with large amplitude displacement evolves differently from the quasigeostrophic vortex and that it is extremely long-lived.