【Objective】The special environment of coastal solonchaks restricts the transformation and utilization of soil nitrogen. Microorganisms in paddy environment mediate ammonia oxidation in rice rhizosphere in a key process of soil nitrogen cycling. However, due to research blindness and outdated technology, the effect of seawater rice rhizosphere effect on the microbial community structure of ammonia oxidation in coastal solonchaks is rarely reported. 【Method】In this study, the seawater rice species ‘Haidao 86’ was used as the experimental material for the pot experiment. The pot experiment was conducted with low (2 g?kg-1) and high (6 g?kg-1) salt concentrations. Soil physicochemical properties and microbial biomass were measured and analyzed, and high-throughput sequencing of ammonia-oxidizing microorganisms was conducted to analyze the effects of different treatments of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) community structure in the rice rhizosphere.【Result】Results showed that after 70 days of rice growth, pH of rhizosphere soil decreased by 0.82 and 0.70, soil organic matter (SOM) content decreased by 6.41 g?kg-1 and 4.46 g?kg-1, humus (HU) content increased by 5.76 g?kg-1 and 4.45 g?kg-1, total nitrogen (TN) content decreased by 0.46 g?kg-1 and 0.37 g?kg-1 for low and high salt concentrations, respectively. Rice rhizosphere effect significantly increased soil microbial biomass carbon, microbial biomass nitrogen and microbial respiration intensity, reaching peak values on the 55th day of planting with 850.0 mg?kg-1, 72.2 mg?kg-1 and 231.9 mg?kg-1?d-1 for high salinity treatment and 546.1 mg?kg-1, 53.7 mg?kg-1 and 171.2 mg?kg-1?d-1 for low salinity treatment, respectively. The rhizosphere effect had no noticeable influence on the Chao1 index, Shannon index and Simpson index of AOA. At the genus level, the dominant bacteria of AOA were norank_c__environmental_samples_p__Crenarchaeota, unclassified_k__norank_d__Archaea, and Nitrososphaera. The rhizosphere effect of seawater rice significantly affected the richness, diversity and abundance of AOB in coastal solonchaks. It can significantly increase the abundance of environmental_samples_f_Nitrosomonadaceae and Nitrosospira. Also, correlation analysis between the AOB community and soil environment showed that environmental_samples_f__Nitrosomonadaceae and Nitrosospira had a significant positive correlation with HU and a significant negative correlation with pH. 【Conclusion】The results of this study indicate that planting seawater rice can improve nutrient cycling in coastal solonchaks, and the rhizosphere effect of seawater rice mainly affects the community structure of AOB under acidic conditions.