A　harvested　predator-prey　system　with　Holling　type　III　functional　response　is　considered.　By　applying　qualitative　theory　of　differential　equations,　we　show　the　instability　and　global　stability　properties　of　the　equilibria　and　the　existence　and　uniqueness　of　limit　cycles　for　the　model.　The　possibility　of　existence　of　a　bionomic　equilibrium　is　discussed.　The　optimal　harvesting　policy　is　studied　from　the　view　point　of　control　theory.　Numerical　simulations　are　carried　out　to　illustrate　the　validity　of　our　results.