This　study　investigated　the　resistance　of　anaerobic　membrane　bioreactor　(AnMBR)　to　lipid　gradients　during　food　wastewater　treatment.　Sodium　oleate　(oleate-Na)　was　added　to　synthetic　food　wastewater　to　simulate　lipids.　Results　show　that　AnMBR　could　adapt　to　a　certain　content　of　lipids　by　stimulate　biomass　growth　and　activity.　As　the　dosage　of　oleate-Na　increased　from　0　to　2　g/L,　the　removal　of　total　organic　carbon　(TOC)　decreased　for　several　days　and　then　recovered　back　to　above　90%.　Such　a　decrease　and　increase　profile　was　also　observed　for　biogas　production　and　methane　yield,　which　stabilized　at　0.61　and　0.41　L/gCOD,　respectively,　after　oleate-Na　addition　was　maintained　at　2　g/L　for　13　days.　Nevertheless,　further　addition　of　4　g/L　oleate-Na　led　to　system　failure　with　a　reduction　of　TOC　removal　and　biogas　production　from　92%　to　62%　and　from　0.61　L/gCOD　to　0.083　L/gCOD,　respectively,　given　a　significant　accumulation　of　volatile　fatty　acids　to　2940　mg/L.　Further　mi-crobial　analysis　showed　that　the　genus　Methanosaeta　enriched　to　50%　with　2　g/L　oleate-Na　addition　and　thus　contributed　to　the　recovery　of　methane　production.　By　contrast,　adding　4　g/L　oleate-Na　inhibited　the　prolifer-ation　of　the　genus　Methanosarcina　to　reduce　organic　biodegradation　and　then　methane　production.