Poly-β-hydroxybutyrate　(PHB)　production　by　halophilic　mixed　consortia　has　great　advantage　in　cost.　PHB　production　by　the　two-step　production　process　using　halophilic　activated　sludge　cultured　from　estuary　sediment　was　investigated.　During　the　continuous　300　d,　the　ability　of　PHB　storage　at　different　F/F　was　assessed　from　the　performance　of　the　long-term　tests,　experiments　of　PHB　production　and　the　observed　kinetics.　The　ratio　of　feast　to　famine　(F/F)　as　an　important　parameter　directly　affected　the　capacity　of　the　PHB-storing　of　halophilic　activated　sludge.　At　a　high　F/F　the　non　PHB-storing　bacteria　became　dominant　in　the　enrichment　reactor,　while　a　low　F/F　was　in　favor　of　the　selection　and　enrichment　of　PHB-storing　bacteria.　Moreover,　the　culture　selected　at　F/F　less　than　0.33　showed　the　best　PHB-storing　capacity　with　a　PHB　content　of　46.7%　cell　dry　weight　and　a　PHB　yield　of　0.358　mg　PHB(mg　Ac)-1.　The　results　obtained　in　the　study　provided　a　guidance　to　the　production　of　PHB　by　halophilic　activated　sludge.　©,　2015,　Chemical　Industry　Press.　All　right　reserved.