In order to study the spatial distribution characteristics and dynamics of Eichhornia crassipes in the Shuikou Reservoir, this study, using 24 unclouded remote sensing satellite images from 2001 to 2009 which covered the Shuikou Reservoir region, reconstructed the spatial structure of Eichhornia crassipes distributed in the mainstream and tributaries, and analyzed the situation of Eichhornia crassipes in the Shuikou Reservoir at different times and different observation zones according to the Linear Spectral Mixture Analysis Method. The results indicate that the outbreak area of Eichhornia crassipes moves from the upper reaches to the lower reaches gradually as time goes on. And some long tributaries with high riparian populations played an important role in the contribution of Eichhornia crassipes in this survey region. The significant factors about the fast growth of Eichhornia crassipes included water eutrophication, low velocity, etc.. It is suggested that local government should take actions to fight against the pollution from the industry, aquaculture, and poultry farming in this area, enhance the supervision and protection of ecological environment, and establish nature reserves. This study can enhance the understanding of the temporal and spatial distributions of Eichhornia crassipes, and then provide fundamental data and theory for managing and controlling the nuisance plants.