Understanding diversity is a hot topic in global ecology because of its significance to biodiversity conservation.To investigate the plant floristic diversity of Xianrendong in Liaoning Province,we conducted plot survey,floristic spectrum,diversity index,correlation analysis and cluster analysis.The results showed that:(1)It is abundant in species composition in Xianrendong,vascular plant consists of 803 species in 379 genera and 109 families,among which,39 species were of fern plants,belonging to 13 families and 17 genera,18 species were of gymnosperm,belonging to 5 families and 12 genera,and 746 species were of angiosperms,belonging to 91 families and 350 genera.It is notable in dominant family,the single-species and few-species genera of angiosperm are rich,which shows some relict phenomenon.The types of distribution are various and complex,the flora is ancient and it has not obvious phenomenon of endemic genera and species;the dominance of temperate elements is obvious and tropical elements are less.This means that it has something in common with tropical flora.(2)Compared with adjacent mountains,floristic Shannon-Wiener index are obvious differences,while Simpson index are not.Shannon-Wiener index of Xianrendong and Culaishan are quite high,Changbaishan and Baishilazi are not.(3)According to the relativity of different mountains flora,their correlation is significant at the 0.01 level,and the coefficients are between 0.811 and 0.997.Cluster analysis showed similarity between Xianrendong and Fenghuangshan,Qianshan,Wutaishan and Xiaowutaishan.The present data indicated that Xianrendong should belong to North China flora.These findings should guide conservation and management efforts to maintain species diversity.