A new matrir Pade approximants (GMPA) based on generalized inverse was at first introduced by [1]. The aim of this paper is to give a Psaan formula for denominator polynomial of GMPA, which should represent the denominator more accurately than the standard determinantal form in [1]. The result derive from Cayley theorem [6] which states that the determinant of a bordered zero-axial skew-symmetric matrix is the product of two Pfaffians. As a important result, the Pfaffian formula of denominator polynomial of type [4/4] for CMPA is established and ls applied to approximate matrix exponential functions.
