Due　to　the　complexity　of　wastewater　treatment　process,　it　is　difficult　to　apply　the　existing　mathematical　models　in　practice.　A　new　model　is　presented　for　the　wastewater　treatment　process　in　this　paper.　This　model　is　based　on　Benchmark　Simulation　Model　no.1　(BSM1)　modeling　method,　and　then　simplifies　Activated　Sludge　Model　No.　1　(ASM1)　which　was　set　up　to　connect　the　secondary　settler　model　dynamically.　Meanwhile,　the　parameters　of　the　model　are　adjusted　by　the　experiment　data.　Finally,　the　practical　data　was　used　to　predict　the　COD　values　of　the　water　quality.　The　results　demonstrate　that　this　proposed　model　is　useful.　©　2010　IEEE.