Abstract: According to the features of hydrology and water resource in karst areas of southwestern China, an index system of evaluating water resource security is established involving five parts， water resource occurrence, water supply quo, water consumption situation, water resource utilization efficiency, and water resource management. With the SPA(set pair analysis), this paper dynamically evaluates the water resource security status of Guizhou Province from 2001 to 2015. The results show that the water resource in Guizhou Province from 2001 to 2007 was in a critical state, while from 2008 to 2015 it was generally safe and relatively safe (except 2009 a draught year). In terms of the change of five factors effecting water resource security, the water resource location depends on the natural environmental factors remarkably, so the H2 value was relatively instable; water supply status was influenced by water conservancy project construction, so the H2 value from 2001 to 2015 rose from 0.53 to 0.90; for water consumption status, as water consumption in production and ecological environmental purpose raised, H3 value declined from 0.87 in 2001 to 0.20 in 2015. In terms of water resource efficiency, it was drew down largely by the water using in Wanyuan GDP and farm land average irrigation, so the H2 value grew from 0.26 in 2001 to 0.88 in 2015, turning into secure and relatively secure ranks obviously. The water resource management was under the impact of increasing municipal sewage treatment rate and raising forest coverage rate, so the H2 value went up from 0.09 in 2001 to 0.58 in 2015, improving the original extremely unsecure rank into critical secure rank. But for some aspects, such as Wanyuan GDP pollution abatement rate, they still have a long way to go; the aspects of water supply, resource utilized efficiency, and resource management all indicate that human behavior has great influence on the water resource security.