Dissolved　organic　matter　(DOM)　can　strongly　influence　the　behavior　and　risk　of　metal　pollutants　in　aquatic　ecosystems.　However,　a　comprehensive　study　on　the　effects　of　DOM　level　and　environmental　factors　on　the　binding　of　DOM　with　Pb(II)　is　lacking.　This　study　examined　the　DOM-Pb(II)　interaction　in　the　river　water　under　variable　DOM　level,　pH,　and　major　ions,　using　fluorescence　excitation-emission　matrices-parallel　factor　analysis　(EEMs-PARAFAC).　Four　humic-like　and　one　protein-like　component　were　identified,　and　the　abundant　humic-like　components　showed　higher　Pb(II)-binding　fractions　(f)　than　the　protein-like　component.　The　f　of　PARAFAC　components　decreased　while　the　conditional　stability　constants　(logKM)　increased　for　the　diluted　DOM,　indicating　the　influence　of　DOM　level　on　its　metal　binding.　The　DOM-Pb(II)　interaction　was　sensitive　to　changes　in　pH,　with　generally　higher　f　and　lower　logKM　at　the　alkaline　condition　due　to　changes　in　the　DOM　conformation.　The　addition　of　major　ions　significantly　decreased　the　fluorescence　quenching　by　Pb(II),　due　to　competitive　effects　and　potential　DOM　conformation　changes　at　elevated　ions.　Overall,　our　results　show　that　the　DOM-Pb(II)　complexation　is　highly　dependent　on　both　the　DOM　properties　and　environmental　factors,　which　have　implications　for　optimizing　the　experimental　conditions　and　for　comparing　the　results　in　different　environments.　©　2022　Elsevier　Ltd