The inversion problem of 2-D and 3-D magnetotelluric data in continuous medium can be changed into fonctionelle variational problem by using finite continuous function family to describe 2-D and 3-D geoelectric models. 采用有限连续函数集描述二维和三维地电模型,可将MT二维和三维连续介质反演问题转变为泛函的变分问题。