As an effective blue carbon sinks to the mitigation of global warm, many studies have showed the changes of soil organic carbon (SOC) of coastal wetland invaded by C4 plant Spartina alterniflora, which is an alien species widely distributed in coastal areas of China. The regions were mainly grouped in Yancheng nature reserve, the Yangtze River estuary, Hangzhou Bay, Minjiang River estuary and Zhangjiang River estuary mangrove nature reserve and other large areas of Spartina alterniflora. These studies mainly compared the SOC distribution of coastal wetland pre-post invasion of Spartina alternifloraand their content variations with the invasion years and different seasons. Through analyzing and integrating relevant studies and data, the paper elaborated the effect of Spartina alterniflora invasion on the SOC of coastal wetland, compared the characteristic of spatial-temporal variations, and analyzed the influence factors on the SOC such as latitude, background plants before invasion, invasion period, hydrological regime, sampling depth and time, soil physic-chemical properties, and so on. Furthermore, in order to provide an important basis for assessment and reasonable regulation of carbon sinks in coastal wetlands, and deepen understanding of the global carbon cycle and global change, some problems of current research were discussed and some advice were put forward, including carrying out extensive long-term observation of carbon sink effect on Spartina alterniflora wetland, using high-resolution remote sensing images to identify plant types and space-time distribution of Spartina alterniflora, considering numerous factors for setting samples field, unifying field sampling method of wetland soil and experiment method analysis of organic carbon, emphasizing and strengthening comparative research on carbon sequestration and carbon release of Spartina alterniflora wetland.