Spartina alterniflora is a notoriously invasive species in the low marsh of China, and meanwhile anthropogenic eutrophication is an urgent and prevalent environmental problem in the coastal wetlands. Soils in the coastal wetland are nutrient-poor, nutrient enrichment may enhance the spread of S. alterniflora towards the non-tidal marsh of the Yellow River Delta. We conducted a 2-year transplant and nutrient addition field experiment to investigate the influence of nutrient enrichment and interspecific interactions on the performance (growth, survival or inflorescence) of S. alterniflora. We found that nutrient addition and species competition did not have significant effects on the variation in performances of S. alterniflora. However, vegetative zones (Suaeda salsa and Phragmites australis), years (2013 and 2014) significantly contributed to the variation. The biomass per stem, survival and inflorescence were much higher in the P. australis than the S. salsa zone (biomass per stem: 1.86 ± 0.17 g vs. 0.82 ± 0.15 g; survivorship: 79% vs. 36%; inflorescence: 40% vs. 2%), and in 2013 than 2014 (biomass per stem: 1.72 ± 0.19 g vs. 0.91 ± 0.13 g; survivorship: 65% vs. 50%; inflorescence: 36% vs. 6.94%), which may be due to the combination of less flooding frequency and high salinity in the S. salsa zone and year 2014. These findings implied that eutrophication may not enhance the spread of S. alterniflora towards the non-tidal wetlands in the Chinese Yellow River Delta.