Abstract: Statistical analysis of the spices, average coverage, average density and average biomass of the seagrass beds in the east coast of Hainan island, And discussion of the change trend of them for fixed-point monitoring in a long term from 2004 to 2013. The results show that, the often detected seagrass species in the east coast of Hainan island, were 2 families 3 subfamilies 6 genera 8 kinds, which were Enhalus acoroides, Thalassia hemprichii, Cymodocea rotunda, Cymodocea serrulata, Halodule uninervis, Syringodium isoetifolium, Halophila minor, Halophila ovalis. The average coverage of the whole seagrass beds was in a downward trend stable, Has decline by 58.60% to 21.12% from 2004 to 2013; The average density of the whole seagrass beds was in a downward trend stable, Has decline by 1756 ind/m2 to 223 ind /m2 from 2004 to 2013; The average biomass of the whole seagrass beds was in a remained stable, mainly for the distribution of Enhalus acoroides was stabilization, with a larger plants and high average biomass, but the distribution of the species as small plants and demanding on the environment has Gradually reduced,and habitat degradation, with the impacted by human activities, Land-source pollution, Ocean engineering and typhoon. This paper hope to through the discussion of the change trend of the seagrass beds in the east coast of Hainan island for nearly a decade, to know the present situation of them, And to enhanced the public's awareness of the protection for the seagrass beds, And to provided scientific theory basis for the protection and restoration of the seagrass beds of Hainan island.