When human activities change land use patterns, many environment elements are being changed accordingly. Well understanding the links between various changes could help to achieve ecological protection through adjusting land use pattern. Mangrove is one of the most valuable ecosystems that have been changed dramatically during the recent decades. Based on Remote Sensing and Geography Information System, along with soil sample determination, we present a quantitative study about the correlations between land use changes and the variations in heavy metal contents in mangrove soil sediments of DongZhai Harbor in China. The results showed that the indices depicting the landscape pattern characteristics had been changed remarkably during 1988 to 2007. Meanwhile, the heavy metal contents had been increasing significantly in mangrove soil. The correlations between landscape indices and metal contents were analyzed statistically. It was found that the metal contents were proportional to the values of main indices, revealing that both the landscape fragmentation and patch shape alternation were closely related to the metal accumulation. Further analyses showed that increasing of aquaculture and residential regions could be responsible for the changes in land use patterns, which subsequently altered the distribution patterns of heavy metal sedimentation in mangrove wetlands.