An　approach　to　design　the　robust　PID　(proportional　integral　derivative)　controller　for　continuous-time　system　with　parameter　uncertainties　is　presented.　H2　performance　and　H∞　performance　are　simultaneously　considered,　and　the　poles　of　closed　system　should　be　sited　in　a　given　region.　A　state　space　parameterization　method　which　allows　to　convert　PID　controller　synthesis　into　LMI　(linear　matrix　inequality)　optimization　problem　is　proposed,　then　the　PID　controller　parameters　can　be　obtained　directly　by　solving　a　set　of　linear　matrix　inequalities.　Numerical　example　is　given　to　illustrate　the　design　procedure　and　its　effectiveness.