This study aimed to know the water quality in Al-Mahawil stream which is a stream from Euphrates River in Babylon governorate by using Canadian water quality index by determining the values of the most important physical and chemical parameters in water stream after taken three study sites along the stream [site 1 (S1), site 2 (S2), site 3 (S3)]. the data was determined seasonally after collection the samples monthly from December 2021 to November 2022. The results first finding out whether the values of these parameters within or above of Iraqi limiting standards of drinking water after that the Canadian water quality index (WQI) has been calculation, then determined if water stream can possibly directly used for drinking purpose or other uses. Generally, results pointed that some of physical and chemicals parameters were in Iraqi permissible limiting of drinking water, while others parameters were above Iraqi limiting standard. Also, the results showed that WQI for Al-Mahawil stream after used all study parameters for calculating was marginal and cannot used directly for drinking purpose. Also, results showed there was a significant differentiation among some parameters with positive correlation coefficients among it.