The problem of robust H∞ reduced-order filtering for uncertain neutral systems with distributed delay is considered. A linear matrix inequality approach is exploited to design a robust H∞ reduced-order filter assuring asymptotically stability and a prescribed H∞ performance for the filtering error system. Moreover，an explicit parameterization of desired robust H∞ reduced-order filter is presented.All these results are expressed in term of the original system matrices without decomposition，which makes the design procedure simple and direct． Two numerical examples are given to illustrate the feasibility and effectiveness of the conclusions.

H∞ reduced-order filter； neutral system； uncertain system； distributed delay