Abstract: The flora of Laoshan Mountain is one of the typical representatives of Shandong Peninsula with some characteristics as follows:it is abundant in species,containing 1045 species of 517 genera,belonging to 129 families.It is notable in dominant family phenomenon;phenomenon of endemic species is obvious;the flora is ancient and single-species and few-species genera of the angiosperm are rich;the types of distribution are various and geographical elements are complex,and dominance of temperate elements is obvious and subtropical elements are plentiful,and it has something in common with tropical flora.The comparison of dominant families of five floras and the similarity coefficient of genera and species are made between Laoshan Mountain and neighbouring mountains.The preliminary results show that the difference of plant floras among Laoshan Mountain,Qianshan Mountain and Xiaowutaishan Mountain is obvious.Floristic data support that Kunyushan Mountain and Laoshan Mountain all belong to the Minor Plant District of the East Lu Hill,but there is certain difference between them.