Biological method using autotrophic bacteria is used for treatment of ammonium in domestic water. In this paper, the authors combined between two methods, Sharon and Anammox to treat the pollution of ammonium. The purpose of Sharon process is controlling an oxidation of ammonium to nitride following the ratio 50:50 for application in next anammox process. Thus, the ratio of ammonium to nitride in the output of Sharon process plays an important factor for the combination of sharon and anammox. The results shown that the optimal conditions for the best efficiency of this biological method. At temperature 35oC. pH as 8.5, and retention time as 5h, the highest percentage of treatment of nitrogen is 97.13 percent. and all the other outputs are in the permission of sanitary standards.