Based on the data of daily water supply and meteorology in Shanghai from May 2010 to December 2013,The paper analyzed the correlation between daily water supply and meteorological factors,and established forecast model of daily water supply.The results show that daily water supply generally presents volatility distribution with one peak and one valley within one year.The daily water supply is the largest in summer (especially in July and August)and the smallest in winter (especially in February). The daily water supply exhibits significant holiday effect and has significant relativity with all the meteorological factors except precipitation., The correlativity of daily water supply with the meteorological factor in the summer half year is much higher than that in winter half year. The water supply is most closely correlated to temperature and has the highest correlation coefficient with the temperature of the day before. Meanwhile,the water supply has extremely sensitive response to the variation of temperature when it is greater than 20℃. The forecast model has high precision and can provide the scientific basis for the meteorological services of urban water plan and reasonable dispatch.