[Objective] The research methods and simulation technology, crucial influencing factors, research focuses, hotspots, and future research directions for rainfall-runoff relationships in China and overseas were analyzed in order to enrich the theoretical basis for the study of land surface hydrological processes and soil erosion mechanisms, and also provide the basis for decision-making regarding regional water resource management practices.[Methods] Based on 828 core journal papers regarding rainfall and runoff in China and abroad during the past 50 years, the CiteSpace visualization software was used for sorting and analyzing the knowledge domain map structure of rainfall-runoff research studies.[Results] ① The study of rainfall-runoff relationships has always focused on the relationship between rainfall, infiltration, surface runoff, and erosion, as well as on the simulation of slope runoff. Research methods have included rainfall simulation, mathematical statistical methods, tracer techniques, etc. In terms of slope runoff simulation, a large number of runoff and confluence models suitable for different environmental conditions have been developed. Although the research methods and simulation techniques have become increasingly advanced, and accurate, follow-up research still needs to be optimized regarding the technical means of simulation testing and the method of applying artificial intelligence (AI) and 3S technology to build a practical regional runoff and confluence coupling model. ② Research studies on the key factors influencing rainfall-runoff relationships, namely surface morphology, rainfall characteristics, and soil properties, have continuously become more in-depth. However, research studies regarding the influence of micro-topographic features and temporal and spatial variations of regional individual rainfall processes on rainfall-runoff relationships, and the comparative studies of surface runoff between different soil types and the same soil types in different natural environments still need to be comprehensively advanced. ③ Most of the domestic research studies have focused on the factors influencing local runoff and confluence under a single soil/vegetation condition through the use of an artificial rainfall simulator. In foreign countries, hydrological models and 3S technology have mostly been combined to study basin scale surface runoff processes, their spatial-temporal variation, and the impact of surface micro-topography. The research scale tends to be comprehensive and in-depth regarding development at both macro-scale and micro-scale. Recently, the research hotspots of rainfall-runoff relationships have focused on karst, runoff plots, forest litter, rainfall characteristics, groundwater recharge, hydrological connectivity, slope, soil physical and chemical properties, water management, etc.[Conclusion] In the future, the advantages of interdisciplinary and technological integration should be further highlighted by strengthening thematic research studies on rainfall-runoff relationships with soil and water conservation, hydrology, and water management in ecologically fragile areas such as karst, arid, and semi-arid areas in order to promote the sustainable utilization of regional water and soil resources and the coordinated development between man and land.