Magnetic field and plasma measurements in the period of 1975-1981 with
0.18-h averages from Hellos spacecrafts are analyzed. Ir is discovere
d that magnetic reconnection phenomena exist in the interplanetary spa
ce. By means of the reconstruction of magnetic field configuration in
the azimuth angle plane, it is found that the magnetic reconnection ev
ent with time scale of the order of day is a significant form of magne
tic reconnection phenomena in the interplanetary space, which consists
of a mediate body (or a plasma bulk) and two magnetic separator lines
. It could originate from coronal mass ejection event or magnetic clou
d in the interplanetary space. Numerical simulation has reproduced the
basic characteristics of the magnetic reconnection events.