Two different mechanisms for field-aligned current propagation, i.e., the Alfv¿n wave and the ballistic motion of energetic electrons associated with a localized source, are examined with linear kinetic theory. The characteristics of these two mechanisms and the relationship between them are investigated as an initial value problem. It is shown that in addition to the shear Alfv¿n waves, the ballistic motions of electrons can also carry currents with the perpendicular scale comparable to the electron inertia length. The propagation speeds of these currents are independent of the Alfv¿n speed. ¿ American Geophysical Union 1989