This article obtains the nonseparable version of wavelet packets on ~a and generalizes the "'unstability" result of nonorthogonal wavelet packets in Cohen-Daubechies to higher dimensional cases. 1 . I n t r o d u c t i o n The wavelet packets introduced by R. Coifman, Y. Meyer, and M. V. Wickerhauser played an important role in the applications of wavelet analysis as shown, for example, in [CMW...