The　enhancement　effect　of　compatible　solutes　on　anammox　activity　under　salinity　stress　was　investigated.　Glycine　betaine　(GB)　was　the　most　effective　in　alleviating　salt　toxicity,　although　all　the　compatible　solutes　(GB,　trehalose　and　ectoine)　were　found　to　be　valid.　Acclimation　potential　of　anammox　biomass　under　salinity　of　30　g/L　increased　significantly　with　GB　addition.　The　recovery　time　in　the　reactor　with　GB　addition　(R-B)　(49　days)　accompanied　by　a　more　stable　stoichiometric　ratio　was　2.65　times　shorter　than　in　the　control　reactor　(R-C)　(130　days).　After　49　days,　the　extracellular　polymeric　substances　and　the　tetrazolium　chloride-dehydrogenase　activity　were　217.9　mg/gVSS　and　38.7　mu　g　TF/gVSS/h　in　R-B,　1.86　times　lower　and　3.17　times　higher　than　the　levels　in　R-C,　respectively.　R-B　possessed　evident　superiority　in　the　aspects　of　microbial　population　proportion.　And　thus,　compatible　solutes　addition　was　regarded　as　one　of　the　feasible　solution　to　counteract　saline　inhibition　on　anammox.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.