Abstract: In this paper,the effects of first and second meridional derivative of Coliolis parameter,west wind and topography profiles(i.e.d2f/dy2),u″,hs″) on ray routes are qualitatively analysed by the use of a simplified mathematical model. The analysis indicates that the conditions of second derivative of the above relevant factors play an important role in the formation of great circle route. A profile of west wind similar with the real atmosphere may result in a "sine wave pattern" of ray. The effects of the shear of west wind,β factor and the slope of topography on the scale of radius of great circle, critical latitude of rays and the amplitude of wave train of teleconnexion are also discussed. Additionally, the characters of critical velocity profile for meridionally trapped wave are discussed.