Based　on　linear　matrix　inequality　(LMI),　a　design　method　of　H　∞　state　feedback　controller　for　a　class　of　uncertain　Delta-operator　formulated　systems　with　pole-assignment　constraints　and　feedback　gain　variations　is　introduced　in　this　paper.　The　existing　condition　of　the　controller　is　translated　into　LMI　form.　The　controller　parameters　can　be　obtained　by　solving　the　LMIs.　When　the　controller　parameters　are　excursive,　the　designed　controller　ensures　the　resulted　closed-loop　Delta　operator-formulated　systems　asymptotically　stable　and　have　the　expected　H∞　performance,　also　the　poles　of　the　resulted　closed-loop　systems　are　located　in　the　assigned　circular　disk　to　satisfy　the　dynamic　characteristics.　A　numerical　example　is　given　to　illustrate　the　effectiveness　of　the　design　procedures.　©　2008　IEEE.