A method for non-invasive mapping (imaging) of the electrical impedance of an object. The present invention provides a method, current density impedance imaging (CDII) which produces an impedance image of object by measuring current density distributions and directly calculating the local impedance values. The method includes making measurements of at least two current density vector fields, J.sub.1 and J.sub.2, within a region of interest in an object and then calculating the logarithmic gradient of local conductivity, .gradient. ln .sigma.(x,y,z), using a formula.gradient..times..times..sigma..times..gradient..times..times..tim- es..times..times..gradient..times..times..times..times..times..gradient..t- imes..times..times..times. ##EQU00001## where {right arrow over (J)}.sub.1(x,y,z) and {right arrow over (J)}.sub.2(x,y,z), are the pair of measured nonparallel current densities at point (x,y,z) and .gradient. denotes the gradient operator.