The karst area in Guizhou Province was classified into five eco-economic categories by the principal component analysis and fuzzy poly-class method.Firstly,classification index system was set up,then was selected in 22 original variables by the principal component analysis.The 75 counties in Guizhou's karst area were classified into the five eco-economic category.The results from this research could present scientific basis for the emphatic drawing up of sustainable developing strategy.