Abstract: Wetland is an essential part of global ecosystems. Wetlands store a substantial amount of environmental change information during their evolution and development process. Wetland ecosystems also store large amounts of carbon, making them as important parts of the global ecosystem carbon sink. As an indicator of climate change and a way to sequester carbon in the long-term, phytoliths have attracted much attention in paleoenvironmental and global carbon sink research. The study of phytoliths and their sequestration of organic carbon in wetland ecosystems is of great significance for exploring changes in vegetation types in wetlands, reconstructing the regional paleoecological environment, estimating the long-term carbon sequestration potential, and regulating the global carbon cycle to mitigate global warming. The relevant Chinese and international research literature have been reviewed and summarized and compared from the following three aspects: the morphology and classification, content and distribution, influencing factors and other basic researches of phytoliths, the extraction technology of phytoliths, and the applications of phytoliths in studies on wetland paleoecological environments, as well as in the studies of global carbon sink potential of wetland ecosystems. The useful future directions for phytolith research are summarized. This review could provide a reference for future researches on phytoliths and phytolith carbon sinks in wetland ecosystems.