【Objective】The water-land ecotone is the last barrier to effectively intercept runoff nitrogen pollutants from entering the water body. Nitrification is a key process of soil nitrogen cycle, and studying the temporal and spatial distribution characteristics and influencing factors of soil nitrification rate in riparian water-land ecotone is helpful to understand soil denitrification in riparian water-land ecotone.【Method】In this study, the spatiotemporal distribution characteristics of soil nitrification rate and physicochemical properties in the riparian water-land ecotone of the Taiyuan section of the Fen River were studied by taking soil samples at different distances, depths and in seasons. By measuring and analyzing the nitrification rate and physicochemical indexes, the main driving factors affecting the soil nitrification rate in the riparian water-land ecotone were explored through Spearman correlation analysis, RDA ranking analysis, and structural equation model. 【Result】The results showed that: (1) The soil moisture content, organic matter, total nitrogen, ammonium nitrogen, and nitrate nitrogen in the water-land ecotone decreased as distance from the shore increased while the bulk density increased. Soil moisture content, electrical conductivity, organic matter, total nitrogen, ammonium nitrogen, and nitrate decreased with the increase in soil depth. Also, in summer, the average values of soil moisture content, bulk density, organic matter, total nitrogen, and nitrate were lower than those in autumn, while ammonium nitrogen was higher than that in autumn. (2) The soil nitrification rate increased first and then decreased with the increase in distance from the shore, and the nitrification rate of surface soil (20.43 mg·kg-1·d-1) was higher than that of the lower layer (8.97 mg·kg-1·d-1). In addition, the average soil nitrification rate in summer and autumn was 15.12 mg·kg-1·d-1 and 14.28 mg·kg-1·d-1, respectively. (3) Soil total nitrogen was the main influencing factor affecting the soil nitrification rate in summer in the water-land ecotone.【Conclusion】 In summary, the results of this study show that in the case of serious nitrogen pollution in river water, it is necessary to fully protect the water-land ecotone within 1 m of the waterbody, which will help improve the ability of riparian soil to intercept runoff nitrogen pollution, thereby protecting river water bodies. Thus, this study provides a scientific basis for the ecological construction, protection, and management of riparian ecotone.