Considering　the　complexity　and　abundant　kinetics　behaviors　in　activated　sludge　wastewater　treatment,　a　cellular　automata　model　(CA)　for　adsorption　and　stabilization　processes　in　activated　sludge　was　established　based　on　the　biological　mechanism　and　the　growth　law　of　activated　sludge,　and　the　simulation　experiment　was　made　using　practical　parameters.　The　results　indicate　that　the　CA　model　can　make　the　complex　adsorption　and　stabilization　processes　reappear,　and　well　describes　the　removal　rate　of　BOD　and　the　growth　of　activated　sludge.　The　CA　model　simulates　activated　sludge　wastewater　treatment　in　the　bioreactor　dynamically　and　visually,　and　exhibits　advantages　of　modeling　wastewater　treatment　by　CA,　while　offering　basic　means　for　similar　complex　systems.