In the intensity inhomogeneity correction of magnetic resonance imaging, since entropy minimization method did not consider space information, a better correction method based on joint information minimization was proposed, which integrated image intensity features with additional spatial image features. The space features referred to intensity derivatives. The joint entropy between image intensities and corresponding derivatives in a corrupted image is greater than that in an uncorrupted one,and it is calculated by using the joint probability distribution of image intensities and corresponding derivatives. The results on simulated brain images and clinical brain MR images show that joint information minimization method between intensities and their second derivatives is good. It can largely decrease the overlap between white matter and gray matter.