The author of this paper tried to judge the change trend of the Xin'an Spring flow by using Kendall rank correlation method, and set up an equation of Xin’an Spring flow attenuation of the years from 1981 to 2006, analyzing the precipitation rule and the changing patterns of groundwater exploitation amount so as to study the influence of the variation of precipitation and groundwater exploitation on the spring flow attenuation. The results show that there has been an obvious attenuation trend in Xin'an Spring since 1980, obeying a negative exponential decay equation; changes in precipitation and groundwater exploitation are the main reasons for the spring flow attenuation, and the spring flow attenuation resulted from groundwater exploitation accounts for 83% of the total flow attenuation.