Considering　the　co-presence　of　body　fluids　and　haloacetic　acids　(HAAs)　in　swimming　pool　waters　(SPWs),　as　well　as　the　potential　for　interaction　among　these　substances　and　membranes,　we　have　conducted　a　systematic　investigation　into　the　impact　of　body　fluid　analogue　(BFA)　on　membrane　performance.　The　minor　impact　of　BFA　on　the　rejection　behavior　of　NF90　was　attributed　to　its　dominant　effect　of　size　exclusion.　However,　for　NF270,　30　mg/L　BFA　increased　water　flux　by　5%,　decreased　NaCl　rejection　from　59%　to　47%,　and　decreased　HAA　rejection　from　88%　to　75%.　The　carboxyl-based　components　in　BFA,　including　citric　acid　(CA)　and　hippuric　acid　(HA),　were　mainly　responsible　for　the　varied　performance.　Carboxyl-based　components　reduced　the　negative　charge　on　membrane　surfaces,　increased　the　effective　pore　size　and　hydrophilicity,　resulting　in　an　increase　for　water　flux　and　a　decrease　for　NaCl　and　HAA　rejection.　The　amine-based　components　(other　BFA　components　with　CA,　HA,　and　salt　excluded)　did　not　directly　influence　the　membrane　performance,　but　their　effect　became　remarkable　under　the　coexistence　of　carboxyl-based　components.　The　amine-based　components　neutralized　the　effect　of　the　carboxyl-based　components　by　forming　hydrogen　bonds.　The　practical　application　of　membrane　technology　for　water　purification　can　be　better　predicted　by　the　underlying　mechanism　for　resolving　the　interaction　among　polyamide　membranes,　organic　substances,　and　trace　contaminants.