The present invention is related to a method for treating high-concentrated organic wastewater, such as night soil or livestock wastewater, which has high levels of nitrogen and phosphorous. In particular, it is related to a method for treating night soil or livestock wastewater having high levels of nitrogen and phosphorous, comprising an anaerobic ammonium oxidizing (Anammox) step and a biopond step. The process for treating wastewater according to the present invention provides good efficiency in removing organic material and nutrients.