Abstract: In general, the strength of magnetic field used in NMR Imaging is nut very high, such as ¹H Imaging, it is less then 1 Tesla. Stability is about 10^-7 and homogenity of magnetic field is less then 10^-6. Such magnet can be provided by a spherical or a ring solenoid system.This report gives the relation between the field configuration and structure parameters of 4 winding spherical magnet and 8 winding ring magnet by means of computer simulution.It shows that these two system will be similar, if they arc designed appropriately. A ring solenoid magnet system can be used in NMR Imaging equipment instead of the spherical system.