In this paper, we present a spatial transformation technique that yields a new search method for adaptive ellipsoid queries. The technique is based on the notion of spatial transformation and efficiently supports adaptive ellipsoid queries with quadratic form distance functions. The basic idea is to transform the bounding rectangles in the original space, wherein distance from a query point is measured by quadratic form distance functions, into objects in the Euclidean distance space. Experiments using various matrices demonstrate the superiority of the proposed method.