The ray theory of geometric optics was applied to visually investigate the propagation of quasi stationary waves in time mean basic flow and interpret the zonal nonhomogeneity. It turns out that squared refraction index (SRI) can be expressed as the derivative of the absolute vorticity with respect to the streamefunction for such a flow and the path is closely related to the spatial pattern of the SRI. The ray has a tendency to travel to a region of maximum SRI (SRI 1) and is difficult to propagate when meeting with a region of minimum SRI (SRI 2). And further analysis shows that the ray, when projecting onto SRI 2 nonperpenticularly (vertically), experiences uni branch (multi branch) refraction. Eventually, the 500 hPa SRI pattern was examined in virtue of measurements, indicating that the scheme can well explain the propagation and multi branch refraction of quasi stationary wave in the real atmosphere.