Yibin Dialect is categorized into Minjiang Area Dialect belonging to the Guanchi Area Dialect of southwest mandarin. The demonstrative pronouns "Nenge" and "Nongge" have particularity in syntax, semantic meaning and pragmatics. According to the research in the synchronic and diachronic situations, it could be found that "Nenge" and "Nongge" are existing in many dialects besides Yibin dialect, while the usage differs. "Nenge" is supposed to originated from the medieval Chinese demonstrative pronoun "Nen" 's colloquial form and its early usage is unclear. The generation of "Nongge" is related to "Nenge" and it is supposed to be differentiated from the early usage of "Nenge". Finally, it can be found that the demonstrative pronoun system of Yibin Dialect has the residual of medieval Chinese demonstrative pronoun components.