In the North-East of Algeria, the Fetzara lake is located 18 km South-East of the city of Annaba. It extends on 17 km from East to West and on 13 km from North to South with a surface of approximately 18600 ha, it was officially classified as a wetland to be protected by the convention "Ramsar". The lake is affected by the phenomenon of salinization, several studies were carried out on the waters and the grounds of the area in order to follow the evolution of salinity, and to highlight its origins. The objective of this work is to follow the geochemical evolution and to measure the degree of salinity of the waters of the lake Fetzara, Annaba (North East of Algeria). To monitor the current state of the chemistry of surface and groundwater in the region of Lake Fetzara, and its evolution in time and space and to assess the phenomenon of salinization, a monitoring of five months was conducted (January to May 2018), including two campaigns of water sampling (January and February 2019), the analyses performed relate to surface waters namely: Oued Mellah, Oued El Hout and Oued Zièd (the inlets of Lake Fetzara) and Oued Meboudja (emptying of the lake) and to the groundwater of the aquifers surrounding the lake. The interpretation of the results obtained from the analyses carried out on the waters shows that the salinity is high, it is more important at the level of the Southeast region (commune of Cheurfa) and that of the Northeast region of the lake (commune of Oued Zièd).