The word "Potuo 陂池',as a document related to the Eastern Han Dynasty imperial mausoleums,is mainly found in Emperor Guangwu's imperial edict to build the Shou Mausoeum. It is crucial to the understanding of the changing of the burial mound of imperial mausoleums from the Western Han Dynasty to the Eastern Han Dynasty. "Potuo" has been interpreted incorrectly in the past for reasons of textual copying and misinterpretation. It should be interpreted as a slightly elevated, uneven slope, which has been correctly interpreted by the Tang Dynasty. The author also corrects the understanding of a relevant sentence.