This paper deals with the problem of Middle-Frequency (MF) approach H-infinity model reduction for nonlinear discrete-time systems in the Takagi-Sugeno (T-S) fuzzy models. The objective is to propose a new design sufficient condition via linear matrix Inequality (LMIs) formulations, ensuring that the error system is stable and has a minimized H(infinity )performance when frequency ranges of noises are known beforehand. Less conservative results are obtained by using the new finite frequency H-infinity performance index is firstly defined, Finsler's lemma and some independent matrices. Simulation example demonstrate the technique and its advantage.