Guizhou Province is a typical karst mountainous area

accounting for 61.96% of the total exposed karst area in China.The rocky desertification in the region is serious

the ecological environment is fragile

and the biological diversity is especially vulnerable.Based on biological diversity

this paper established a comprehensive assessment index system of biological diversity using five indices of species richness

diversity of ecosystem types

completeness of the vertical stratification

species endemism

and number of invasive species.Using the established system

we evaluated the biological diversity of each county( districts

cities)for the entire Guizhou Province.The overall results were reported in four grades: excellent

good

average

and poor.There were 10 counties rated as excellent

accounting for 11.36% ; 29 counties as good

accounting for 32.96%; 39 counties as average

accounting for 44.32%;and 10 counties as poor

accounting for 11.36%.The regions with better grades are in remote mountain areas in northeast and southeast of the province

while the areas with lower grades mainly lies in flat terrain in central province.