Abstract: The effects of various elevatigns, locations and ages of plantings on the characteristics and biomass of Spartina alterniflora were studied in Luoyan bay, Luoyan County, Fujian Province, 26˚308′N. The results showed highest density, height, below ground and above ground biomass of S. alterniflora communities planted near the high water of neap tide. Better growth and more biomass have been observed in the region of river mouth with abundant fresh water supply and mud deposit of high fertility than in the region far away from the mouth with mud of high salinity and low fertility. The under ground biomass of S. alterniflora communities increases with their age. However, the biomass above ground and the biomasses of both above and below ground were highest in 3 year old communities, higher than those of 4 year old ones.