Dissolved　organic　matter　(DOM)　in　sewage　effluents　from　Beijing＇s　wastewater　treatment　plants　(WWTPs)　were　characterized　and　compared.　Results　revealed　that　the　characteristics　of　DOM　in　sewage　effluents　were　related　to　the　nitrification　degree,　sewage　property　and　the　adopted　technology　of　WWTPs.　Good　nitrification　contributed　to　the　degradation　of　effluent　organic　matter　and　increase　the　humification　degree　of　effluent.　The　physical　entrapment　effect　of　membrane　biological　reactor　(MBR)　as　well　as　its　longer　sludge　retention　time　decreased　the　humification　degree　of　effluent,　while　a　portion　of　organic　matters　with　high　molecular　weight　were　still　retained.　Aerobic　biofilm　with　a　longer　sludge　retention　time　might　induce　the　aggregation　of　protein-like　soluble　microbial　products.　Comparing　with　municipal　domestic　sewage,　the　characteristics　of　DOM　from　WWTP　feeding　with　domestic　and　industrial　mixed　sewage　displayed　obvious　differences.　©　2011　IEEE.