Abstract: Scientifically and objectively assessing the impacts of sea level rise on the coastal ecological environment is the key to achieve rational utilization and development of coastal resources. By using the Sea Level Affecting Marshes Model (SLAMM), we have made quantitative simulation and projected the short-term (2017—2030), mid-term (2017—2050) and long-term (2017—2100) sea level rise impacts on the Guangzhou coastal wetland change of area and spatial distribution, and further performed quantitative assessment of changes in the ecosystem service value. The results show that sea level rise in the short-term causes the spatial distribution of coastal wetlands towards significant fragmentation, and the mid-term and longterm impacts are relatively stable. The salt marsh, reed marsh and mangrove areas have been decreased dramatically, while the estuary water areas have continued expansion, and fluctuation changes occurred in the mudflat areas; The total value of ecosystem service is characterized with “decrease (short-term)-increase (midterm)-decrease (long-term)”, fluctuation, but finally the total amount of value was decreased, with the reduced sum of around 4,354.925,9 million yuan, of which the value of fishery production and education scientific research were decreased drastically, the value of pollution purification was increased significantly, and the fluctuation of interference regulation value was significant.