A three-dimensional and time-dependent numerical study was carried out to clarify temperature and oxygen distributions in a silicon melt under rotating magnetic fields. Simulations were carried out to study the effects of strength and frequency of rotating magnetic fields on temperature and oxygen distribution in the melt. The results of calculations showed that the flow motion consists of a primary flow in the azimuthal direction and a secondary flow in a meridional plane, which have three-dimensional and time-dependent structures, and that the strength and frequency of the rotating magnetic fields affect the time-dependent structure of the flow. It was found that the secondary flow in a meridional plane enhances heat and impurity transfer from the crucible wall to the solid-liquid interface of silicon through the melt. (C) 2002 Elsevier Science B.V. All rights reserved.