This paper focused on the effect of two factors on karst springs in northern China. The Liulin Springs, as a representative of karst springs in northern China, was selected as the study area. By analyzing the spring flow and groundwater development, it is found that the Liulin Springs were in natural conditions before 1973. The result shows that from 1974 to 2005, the contribution of climate change to spring flow decaying accounts for only 8. 1%~8. 6% of total effect by human activities, suggesting that the latter plays a vital role in decay of spring flowing. Of all the human activities, groundwater development accounts for 20%~35%, while other factors such as over-exploitation of groundwater in vicinity areas, construction of reservoirs, ecosystem destruction, and mine drainage etc. account for 65%~80%.