Abstract: Objective To understand the trend of pH value changes in water supply system in Xinjiang and its relationship with other water quality parameters. Methods The water quality monitoring data of 87 monitoring units for urban and rural water supply plants in Xinjiang Uygur Autonomous Region from 2020 to 2022 were collected,and the data were analyzed. Results From 2020 to 2022,a total of 18 656 water samples were monitored,with pH values[M（P₂₅,P₇₅）] of 7.78（7.40,8.00） and the total qualified rate of 99.69%. The pH qualification rate showed an increasing trend year by year from 2020 to 2022（χ²=16.045,P<0.01）. There was a statistically significant difference in pH values between urban drinking water and rural drinking water under different sampling types（χ²=14.213,P<0.05）. There was a statistically significant difference in pH values between surface water source drinking water and groundwater source drinking water under different water source types（χ²=116.034,P<0.05）. The total hardness,chroma,and chloride significantly negatively predicted the pH value of water（β=-0.101,-0.192,-0.069,all P<0.01）,while sulfate significantly positively predicted the pH value of water（β=0.106,P<0.01）.Turbidity and chromaticity values were correlated with the probability of predicting the pH value of drinking water to be qualified. Conclusion pH value is associated with some water quality parameters and can reflect water quality situation. In different water source types,the relationship between water pH value and other water quality parameters is different,and it is affected by other physical and chemical parameters.

Key words: Drinking water, Water pH value, Water quality monitoring, Regression