The method [2] of testing stability of discrete systems using continued fractions is investigated. A new

-domain continued fraction expansion method of the discrete reactance function is presented. Using the new method, the number of discrete reactance functions that have to be generated in order to proceed in the continued fraction expansion is reduced from

, using the method in [2], to

for even

and to

for odd

. This results in considerable simplification in testing stability. An illustrative example is included.