The major environmental risks associated with soil and eventually crops or ground waters contamination by treated wastewater (TWW) application are due to its chemical composition. For this purpose, we have carried out an experiment with three small parcels irrigated with TWW and three others irrigated with freshwater (FW) in an irrigated area at north of Tunisia. The chemical properties of soil before and after being cultivated by corn crop were followed. Soil samples were collected from depths of 0-30, 30-60, 60-90, 90-120 and 120-150 cm and were analyzed for pH, EC, SAR, Na, K, Ca, Mg, Cl, Zn, Cu, Co, Cd, Pb and Ni. The results showed that TWW irrigation increased significantly (P≤0.05) the soil EC, Na, K, Ca, Mg, Cl, SAR, Cu, Cd and Ni but not significant (P≤0.05) effect was shown for the soil pH, Zn, Co et Pb as compared with fresh water(FW) and control soil. The accumulation of EC, Na, Cl, SAR, Zn and Co increases with the soil depth. While no significant effect of depth were observed for K, Ca, Mg, Cd, Pb and Ni. It was, also, shown that accumulation of these elements in the soil decreased significantly in the FW treatment as compared to the control.\nKe