A study was conducted on sixteen water purification plants in Kirkuk governorate to evaluate the treatment of water in them, where physical and chemical tests were conducted for raw water and treated water for a period of (6) months from December until May. Temperature, turbidity, pH, Total Dissolved Solid (TDS), Electric Conductivity (EC), alkali, Total Hardness (TH) and calcium (Ca +2 ) were measured. Water quality index Canadian method (CCME) was used to classify raw water quality and treated water. The results showed that the raw water for all stations was classified as category (4) (bad) during the study period. The treated water was different for the treatment plants. Two of the treatment plants recorded good efficiency in water treatment (AL-Shallalah plant and Sin AL-Thiban) the treated water remained in category (2) (good). While the water quality of AL-Mosanaa plant indicated that there was a problem in the treatment of water in this plant, the treated water remained in category (4) bad during the study period. Water quality index fluctuated for other plants during the study period. The study also showed that alkali values of all stations were higher than the allowable limit for raw water and treated water.