Global climate changes and human activities have led to the shift in vegetation dominance from grass to shrub in many coastal wetland ecosystems, which hasconsequently changed the patterns of global vegetation. This paper reviewed the patterns of shrub encroachment in coastal wetlands world widely. We analyzed the influences of global climate factors, such as the minimum tempera ture, air CO2 concentration, precipitation as well as sea level rising, on shrub encroachment in coastal zones. We also discussed the ecological effects of shrub encroachment on coastal environments, biodiversity and the blue carbon functions of coastal wetland ecosys tems. There are, however, important information gaps and technology problems in current researches. Therefore, combination of varied high-resolution remote senses data is needed to accurately evaluate the spatial distribution of shrub encroachment in coastal wetlands on local, regionaland global scales, respectively. Researches in the future should also focus on the feedback mechanism of shrub en croachment in the coastal ecosystems. Finally, we give somecluesforresearches on the shrub encroachment ofcoastal wetlands in North and East China, which is quite different from the mangrove encroachment in South China.