The leachate contains various types of organic and inorganic matter which can pollute aquatic environments if they are not properly treated. The choice and the efficiency of treatment techniques depend on the characteristics of the leachate, these characteristics change from one region to another and according to time and seasons. The objective of this study is to prepare synthetic leachate based on the characteristics of real leachate (the case of the Al Hoceima controlled landfill), in order to carry out tests of treatability of this synthetic leachate by controlling the different analysis parameters, in order to be able to choose the suitable treatment technique for the type of leachate to be treated. In our case for the leachate from the controlled landfill of Al Hoceima city, the characteristics are very variable; COD varies from 12365 to 33600 mg(O₂)/L, ammonium varies between 1921 and 4060 mg/L, chloride from 4660 up to 7196 mg/L. In fact, this solution was made from organic (CH3CO₂H, CH₃CO₂Na) and inorganic compounds (MgSO₄, CaCl₂, Ca(OH)₂, NH₄Cl, KOH, MgCl2), the various analyzes of this solution gave values comparable to the real solution.