The　effect　of　continuous　feeding　on　the　stability　of　aerobic　granular　sludge　(AGS)　was　investigated.　A　lab-scale　sequencing　batch　reactor　(SBR)　seeded　with　mature　AGS　was　operated　for　30　days　under　a　continuous　feeding　pattern.　Under　these　conditions,　part　of　the　AGS　disintegrated,　and　much　tree-like　sludge　and　some　filamentous　bacteria　grew　on　the　surface　of　the　remaining　AGS.　During　the　first　13　days,　the　sludge　volume　index　(SVI)　increases　rapidly,　and　then　becomes　stable.　Quantitative　investigation　of　the　extracellular　polymeric　substances　(EPS)　indicates　that　extracellular　polysaccharides　decrease　while　extracellular　proteins　first　increase　and　then　decrease.　After　about　15　days,　the　content　of　EPS　becomes　steady.　EPS　staining　shows　that　the　proteins　contribute　to　the　formation　of　the　core　of　the　AGS,　whereas　the　α-glucopyranosyl　polysaccharides　and　β-D-glucopyranose　polysaccharides　accumulate　in　the　outer　layers　of　the　AGS.　After　30　days,　the　positions　of　proteins　and　α-glucopyranosyl　polysaccharides　change　slightly,　but　the　number　of　β-D-glucopyranose　polysaccharides　accumulated　at　the　outer　layer　increases　greatly.　EPS　staining　also　indicates　that　the　stability　of　AGS　is　dependent　on　the　protein　core,　and　β-D-glucopyranose　polysaccharides　could　be　used　to　evaluate　whether　the　AGS　is　stable　or　not.　The　results　of　this　study　show　that　continuous　feeding　is　not　favorable　for　the　stability　of　AGS　because　of　the　low　substrate　gradient.