Compound characters in oracle bone inscriptions refer to the form of two or three oracle bone characters combined together. These characters, formed after combination, are called compound characters and represent one of the structural features of oracle bone scripts. The phenomenon of compound characters is prevalent among river names in oracle bone inscriptions. Based on this observation, we propose that the formation of river names in oracle bone inscriptions was initially the combinations of geographic names and rivers, and these compound character forms have generally gone through a development process from separate characters to compound characters. Through the study of the structure formation of river names in oracle bone inscriptions, a deeper understanding of the people’s perceptions of river systems and geographical environments during the Shang Dynasty can be obtained, as well as the relationship between geographic names and rivers.