Abstract: Based on the 1992〖KG-*2〗-〖KG-*7〗2007 remote sensing images and field survey data, and by using the landscape ecology theories and the method of conversion m atrix, the spatiotemporal dynamics and landscape pattern of Spartina alternifl ora in Yancheng coastal wetlands were analyzed by GIS. The results showed that the total area of S. alterniflora along the whole coastal beaches of Yanche ng increased from 3561 hm2 in 1992 to 14491 hm2 in 2007, with a growth rate of 30694%. In 1992〖KG-*2〗-〖KG-*7〗2007, the total area of S. alterniflora  conversion-in and conversion-out was 26291 hm2 and 15361 hm2, respectiv ely, and the S. alterniflora community in the core area of Yancheng National Nature Reserve expanded from 597 hm2 to 2814 hm2, with an annual growth rat e of 2474%. The S. alterniflora community transformed from scattered patch es in estuarine regions into continuous belt pattern mainly distributed in the p eriphery of coastal wetlands from Sheyang River to Liangduo River. Its centroid moved to the southeast, with a distance of 292 km. The average area of patches increased from 1992 to 2002, and then decreased from 2002 to 2007. The largest patch index and area-weighted contiguity index increased year by year, and the shape of patches tended to be more regular.

Key words: ecosystem service value, land use change, comparative analysis, excessive loss.