The water level is very low in karst area and the water resources leakage is serious,so it is difficult to accumulate water resources and its development level and utilization rate is low too.In addition,the soil layer is not consecutive,the vegetation structure is simple and the environment is fragile.All these factors lead to the water resource carrying capacity in karst area is low relatively.With the development of economy,science and technology,the water resource carrying capacity in karst area displays its own evolved rules.And there are many factors that affect the evolution of water resource carrying capacity.Taking Guiyang city as an example,this article selects three components from 15 indexes through component analysis method.And then using entropy value method to bestow weights to the three components,the scores of Guiyang's water resource carrying capacity from 1998 to 2003 can be obtained.From the scores it is known that although the two main pressures(population and economic development)of water resource carrying capacity increase year by year,on the whole Guiyang's water resource carrying capacity evolved to a good direction in the six years except 2002.In 2002,the amount of water resources is very large,however,the water resource carrying capacity(especially the unit water resource carrying capacity)dropped viewing from the indexes.Affected by karst,the water resource carrying capacity is limited greatly.With the development of the technology and the improvement of waterresources development level and utilization rate,there is still surplus water resource carrying capacity in the karst area.