Abstract: In this paper, the characteristics of nonlinear barotropic Rossby waves is further studied in natural coordinate systems under certain assumptions. It is pointed out that the essential equation governing Rossby waves is the pendulum equation or an expresion similar to the Sine-Gordon equation. Some complicated trajectories of fluid parcels and periods of nonlinear vibration in the atmosphere are obtained . Furthermore , a few complicated flow patterns of stationary Rossby waves are given and propagation of phase and energy of nonlinear Rossby waves along streamlines proved. All these results are of significance for further understanding the processes of atmospheric dynamics and interpreting some phenomena observed.