The research entitled “The Tradition of Paying Homage to Kudpeng Guardian Spirit in Phon Thong District, Roi Et Province: A Functional Approach Analysis” aims to analyze the functions of the tradition of paying homage to Kudpeng Guardian Spirit on Phon Thong society and people. It also studies the belief of Phon Thong people towards this tradition.This research is considered as a folklore study and the field trip took place at Kudpeng Shrine in Phon Thong District, Roi Et Province. To collect the data, the folklore research methodology regarding the naturalistic research approach on indigenous cultural analysis was adopted. The data were collected through video and audio recordings as well as observation techniques. To analyze the data, the functional approach was employed.The findings reveal that the tradition of paying homage to Kudpeng Guardian Spirit plays an important role on building up people’s confidence as they believe that this tradition will bring in good fortune to the people themselves, their families, and society as a whole. Most importantly, another function of the tradition of paying homage to Kudpeng Guardian Spirit is to cast lots to determine the fertility of their crops, food, and the amount of rainfall during the farming season by putting a turtle into a pot of boiling water.Besides these, Phon Thong people believe that Kudpeng Guardian Spirit protects them from all kinds of disasters and the forest under his protection will be fertile forever.