This paper presents a perturbation analysis of the canonical subspaces of a matrix pair (A,B). It is shown that if the perturbations in the matrices A, B do not change the ranks of each matrix, then the perturbation bounds of the canonical subspaces depend upon the perturbations and the scaled condition numbers of the matrix pair, as well as upon the gap of the corresponding canonical correlations. (C) 1998 Elsevier Science Inc. All rights reserved.27941699135151