Abstract: In order to accurately monitor the water quality variation of the water inrush sources in the underground mine and to eliminate the temperature affected t 0 the pH value, based on the conventional pH value applied to monitor the water inrush sources in the underground mine, a pH value temperature compensation model was provided based on the PSOR iterative algorithm in order to provide a new basis to the early warning of the mine water inrush. With the curve ftting method, the E-p H value model of the several conventional mine water inrush sources was established with the method. The related data processing was conducted. Finally, the pH valu e monitoring was applied to the Ordovician limestone water, the roof sandstone water of No.1 seam and the roof sandstone water of No.9 seam. The experiment result s showed that when the temperatures of the three water samples was 5, 15, 25, 35 and 45。C，the max pH value error of the water samples measured with the conventi onal method would be 0.85 and the max error value of pH value with a temperature compensation of the coal sample was 0.13 only. The application of the system could effectively overcome the large error disadvantage existed in the conventional temperature measurement. The PSOR method could be applied to the temperature compe nsation of the pH value and thus accurate measurement of the liquid pH value could be realized.