This thesis aimed to investigate and gather the data concerning Khun Phaen Folklore in Changwat Kanchanaburi and Changwat Suphanburi. This is to analyze the characteristics of the said data and to make the comparison of the collective memory of Khun Phaen based on the variety of the folklore found in these two provinces. In this regard, the concept of collective memory was employed in the analysis. Khun Phaen Folklore as found in Changwat Kanchanaburi and Changwat Suphanburi can be categorized into 5 groups: 1) place names and other names, 2) statues and monuments, 3) sacred objects, 4) paintings and 5) folk songs. According to the research results, Khun Phaen Folklore in Changwat Kanchanaburi was different from the one of Changwat Suphanburi. That is to say that, for the former, it concerned Khun Phaen life when serving as the soldier and town ruler, while, for the latter, it focused on his novicehood life. With respect to the comparative study on Khun Phaen Folklore, Khun Phaen was recognized as the local hero of both provinces. This conformed to the construction of collective memory of Khun Phaen in the lens of folklore in these two provinces. In particular, the construction of collective memory as found by this study was: the conservation and promotion of places concerning Khun Phaen to conserve and build a site for the collective memory of Khun Phaen in the local community, the construction of statues and monuments for the continuation of the legend and ritual of Khun Phaen to strengthen the belief of his existence, and the introduction of slogan and naming to depict the relevance of the local community to Khun Phaen. Besides, there were 3 elements for the construction of collective memory: the continuation of collective memory in the local community, the struggle for cultural identity advantages and the tourism economy promotion. According to the analysis of collective memory, it was revealed that Khun Phaen in the collective memory of Kanchanaburi people was the great warrior and respectful town ruler, while, for Suphanburi people’s collective memory, Khun Phaen was a local man who ordained and became skillful in the literacy with expertise in superstition.