Abstract: Based on the data of the sample plots,study was conducted on species diversity of plants by using species richness,Simpson index,Shannon-wiener index and Pielou index in Gupo Mountains of Guangxi province,and also on interspecific relationship between dominant species of plants by using X² -test for the 2×2 contingency table,Pearson correlation analysis and Spearman's rank correlation analysis.The results were as follows:(1)the four diversity indexes showed the same trend and the order of different levels of species diversity is:shrub layer> herb layer> tree layer.(2)the study on the relevance of the dominant species by stratification found that the dominant species mainly have no significant correlation,shrub layer has the most kinds of species which have significant and highly significant correlation,the following is herb layer,and tree layer is the least. This shows that the development of dominant species on the main layer of the vegetation performance for the mutual competition was changed by the big-to-small trend. The climax community is either single-gifted community or more-gifted community.Obviously,the vegetation of Gupo Mountains is far from the perfect state.The above study can be of some reference value and significance to management and rational development of forest resources and evaluation of park resources and development.

Key words: Gupo Mountains, species diversity, interspecific relationship, dominant species