The use of water resources for the satisfaction of socio-economic needs depends on their quality. In the actual context of socio - economic development, the water resources of the planet are strongly affected so that their protection has become a major problem of humanity. The main purpose of this study is to assess the water quality of the Danube River, the Braila - Calarasi section (km 375 - km 175) in 2011, through physico - chemical parameters. In the same time, it was carried out and an analysis of similarities and differences in the composition of the physical - chemical river water between stations. The water samples were taken from three main points, the Bala arm and sandbar Caragheorghe (km 347 - km 343) (station 1 - S1), the Epuraşu Island (km 342- km 341) (station 2 - S2), Caleea arm (km 197 - 195) (station 3 - S3). The physico - chemical parameters used in this study are: the regime of temperature, pH, dissolved oxygen (DO), nutrients N-NO3, N-NO2, N-NH4, P-PO4 cations Ca2+, Mg2+, conductivity and turbidity. We conclude that in the Calarasi - Braila river waters fall into third quality class (moderate ecological status).