Rising sea levels caused by climate change is the major driving force in landward migration of mangrove communities,and its overlying plants can slow down the rate of sea-level rise deriving from sediment trapping. In the paper,six sediment cores were collected from the typical mangrove swamps in Guangxi,China. Based on moisture contents and ~(210)Pb analysis,the average sedimentary rates were calculated using the CIC model in different cases of considering/no-considering sediment compaction. Compared between the rate of regional sea-level rise and the sedimentary rates, it reveals the relationship of landward mangrove migration in response to relative sea-level rise. The sediment compaction rates are between 0.16~0.78 cm/a, but no-considering sediment compaction fates are approximately 1.00~1.34 times (mean 1.12 times) more than the rates of sediment compaction. The sediment compaction rates are lower than the rate of regional sea-level rise in mangrove swamps of Yingluo Bay and Dandou Sea, however, the sediment compaction rates are obviously higher in the Maowei Sea. Owing to the seawall preventing the landward mangrove migration,the mangrove plants are currently under threat from sea-level rise in the Yingluo. Bay and Dandou Sea. It is obviously different with previous reports. Taking no account of sediment compaction, the sediment rates were be overestimated in the recent studies.