As one of the leading causes of the loss of global biodiversity, biological invasion severely threatens the existence of native species and destroys the structure and function of the original ecosystem. Alien plants,an important category of invasive species, can significantly change the local vegetation communities, and have a major effect on other related biological groups. Birds, which are positioned at the higher trophic levels in ecosystems, are particularly sensitive to changes in habitats caused by invasive plants. The typical smooth cordgrass (Spartina alterniflora) continued to spread since it was introduced to China's coastal regions, which provided the impression that the smooth cordgrass might decrease biodiversity and degenerate the ecosystem. In this study, we systematically elaborated the ecological effects of the invasive smooth cordgrass on avian habitats, food resources, reproduction, and communities. The negative effects of the invasion mainly included:(1) the unsuitability of the altered vegetation community structure for avian roosting, nesting, and foraging; (2) the decrease in richness and diversity of avian food resources; (3) the remarkable decline in the number of populations and species diversity of native birds. The invasion of smooth cordgrass in China's eastern coastal wetlands had changed the distribution pattern of native vegetation and birds drastically. However, some small passerines could adapt to the habitat of long time invasion by the smooth cordgrass gradually. Indeed, several non-native birds have adapted to the newly formed ecological environment, which provided free ecological niches for them, and consequently enriched the diversity of native species in some extent. Therefore,the rapid weeding of smooth cordgrass might be detrimental to those birds, which have already adapted to the smooth cordgrass and become dependent on it. In summary,further research focusing on long-term, large-scale, and multifactorial monitoring, and multi-species comparisons, are necessary for comprehensively evaluating the effect of invading smooth cordgrass on the avian community and the entire ecosystem, with the aim of establishing ecological evaluation models and adopting scientific and efficient management countermeasures against the invasion.