SUMMARY
The present study consists in the evaluation of the quality of waters of two sources of the municipality of Tissemsilt, while making physicochemical analyses to determine the drinkability of waters and its nutritional qualities, and microbiological analyses to assure the absence of indicator germs of pollution.The results obtained for both sources and for the most part of the physicochemical parameters answer actually the Algerian standards, with the exception of the Nitrate (NO3-) for the source Ain LOURA which presents values between 146,7 and 198,9 mg/l what exceeds widely the standards fixed by the Algerian legislation (50 mg/l). Also the results of the microbiological analyses show a contamination translated by the presence of various germs (aerobic germs and total coliforms) for Ain SFA, and (fecal coliforms, streptococci and the sulphite-reducing Clostridium) for the source Ain LOURA.