Abstract: To investigate the variation of physicochemical parameters and pollution characteristics of karst groundwater under the highintensity impact of tourism activities, the physicochemical parameters of the Shuifang spring, which located in the core region of the Jinfo Shan World Natural Heritage Site, were continuously monitored during the high season of tourism activity (winter). Results indicated that characteristics of water quality inthe Shuifang spring exhibited natural background conditions before the peak travel period, physicochemical parameters showed small fluctuations. The pH, specific conductance(SpC), turbidity, dissolved oxygen (DO), calcite saturation index(SIc), partial pressure of carbon dioxide (pCO2), Ca2+ ,Mg2+ , HCO-3fluctuated sharply with the arrival of the peak period. The sewage fromtourism activities containedorganic maters and acidic materials that were needed bymicrobes.Microorganisms can produced carbonic acid. The carbonic acid and other acidic materials increased dissolution of karst underground conduits, madethe concentrations of carbonate dissolution properties, as Ca2+ , Mg2+ , HCO3- , elevated (concentration growth percentageswere 10%, 22%, and 26%,respectively). Because of different ingredients of pollutants in the sewage, the K+ , Na+ , Cl- , PO3-4, SO2-4concentrations rose more obviously(concentration growth percentageswere 257%, 273%, 286%, 750%, and 93%, respectively)than otherhydrochemical parameters. Large quantities of sewage poured into the groundwater hadled the SpCrose, DO dropped, water purification ability degraded, and thus groundwaterbeen vulnerable. According to the evolutional characteristics of physicochemical parameters in karst groundwater influenced by tourism human activities, we established a conceptual model. The results of the study indicate that the groundwater is rapid respondingand susceptible to intensively human activities in short time, and is suffered from pollution easily.