Korea possesses the world’s highest per capita consumption of seaweed and a food culture that includes eating seaweed soup. According to Sesi-Pungsok (seasonal customs) and Hangukinui-Llsaenguirye published by the National Research Institute of Cultural Heritage, the uses of seaweed soup other than childbirth included rituals such as Seolnal, Daeboreum, and Chilseok, as well as harvest ritual, traditional weddings, Dragon King ritual, Antaek, memorial services, birthdays of the deceased, Samsin (Goddess of childbirth), Sosamsin (Goddess of bovine childbirth) and exorcising wandering spirits. The frequency of appearance was highest in terms of season during the New Year’s period from Seolnal, Daeboreum, as well as in July (Chilseok) and October, when harvest ritual and Antaek are performed. By customs type, it was most frequent in the order of holidays and seasonal festivals > Dragon King rituals > weddings and Sinhaeng (traditional wedding procession). The frequency of appearance by type of custom showed high usage in rituals for purifying evil spirits or bad luck, such as weddings and Sinhaeng, exorcism ritual for wandering spirits and warding off evil from a funeral. The frequency of appearance by region showed a tendency for severe bias to appear depending on the western and eastern regions of the Korean Peninsula. Among the forms of seaweed soup that appeared, plain seaweed soup, which contains no meat or animal-based seafood, accounted for the majority.