An analytical calculation on the behavior of point-defects in growing silicon crystals was performed with some types of temperature field, the isotherms of which are inclined, spherical and toroidal. The calculation concluded that the saturation of the point defects is affected not only by the temperature gradient, the derivative of it and the pull rate but also by the inclination and the curvature of the isotherms. Quantitative formulation will be given later. (C) 2002 Elsevier Science B.V. All rights reserved.