Factors affecting salt accumulation in topsoil and their intensity were studied with the application of the path analysis method, which was performed in the saline region of Lower Yellow River Delta. Results indicated that the process of salt accumulation in topsoil was generally affected by salt source distribution, chemical properties of ionic composition, soil physico-chemical properties, groundwater status and regional climatic conditions. In dry seasons the extent of soil salinization was relatively high and the top enrichment of soil salinity was apparent across the study area. The intensity of salt source distribution to salt accumulation in topsoil was the most significant, followed by chemical properties of ionic composition, while the effect of topsoil physico-chemical properties and groundwater status on salt accumulation in topsoil was via other factors. Subsoil salinity reflecting salt source distribution, plus sodium absorption ratio (SAR) and Cl-/SO42-reflecting chemical properties of ionic composition were crucial factors of salt accumulation in topsoil. The research results can serve as a reference to the scientific management, amelioration and utilization of saline soils in the Yellow River Delta.