Abstract: In this paper, using the data of 52 ionosonde stations distributed in the world, the developments of the ionospheric disturbance during the magnetic storm on July 8, 1958 and the propagation direction and velocity of this disturbance are inrestegated. The following conclusions are obtained.1. The ionospheric disturbance for each sector started from polar regions. Besides this characteristics, after the beginning of the magnetic storm, there is a disturbance center in the equator area of American sector. The disturbance in the nearbgy regions are controlled by it.2. The disturbance developed from high latitude to low latitude.3. The frontal surface of the disturbance is almost perpendicular to geomagnetic field lines. It means the disturbance propagates along magnetic lines. The propagation velocity for the disturbance is between 105and 600 m/s.