Community expansion and succession are important processes in wetland ecosystems. Studying the expansion of restored plant communities contributes to understanding the dynamic evolution of wetland restoration, and is of great significance. A restored Carex appendiculata tussock wetland in Sun Island was selected for study and a field survey and 35 technology carried out to identify Carex tussock spatial distribution and expansion processes. We also analyzed relationships between the Carex community and environmental variables to clarify the main drivers of community expansion. The C. appendiculata tussock community expanded 29.91 m to southwest and 13.27 m to the east, respectively, with a total expansion area of 722 m(2). Carex tussocks in the expansion area had significantly higher leaf area, individual plant biomass, hummock diameter and volume, which were positively correlated with soil water content and water depth. Redundancy analysis (RDA) demonstrated that water depth was the major driving force for Carex tussock community expansion. Additionally, interspecific competition between Phragmites australis and Carex tussock may inhibit Carex community expansion. Moreover, as water depth affected the development and expansion of Carex tussocks, hydrological regulation can be used to accelerate the recovery and restoration of Carex tussock wetland. This study provides a specific technology for the restoration of Carex tussock wetland.