Abstract: The authors set up a interrelated model between precipitation and water yield of allotment No.2 of Nantong Coal Mine by time series analysis with multivariation. This model is used into the forecast of. water yield and the results. show that delay-periods of water yield of allotment No. 2 to precipitation are one month, three months and three years respectively. The forecastive values from the model gave quite good agreement with the measured values.