We have obtained the injection function for the part of the storm-time depression which is related to the cross-tail current and corresponding currents on the magnetopause. This injection function is QTC=-&kgr;U/S, where U is the electric potential difference between the dawn and dusk sides of the magnetosphere, S is the equatorial cross-section of the stable trapping region, and &kgr; is a coefficient varying from 0.5 to 1.5 depending on the state of the magnetosphere and solar wind pressure. The injection function QTC appeared to be close to the observed one for the Dst-variation. ¿ American Geophysical Union 1996