齐 is a simplified form of 齊. This thesis examines the evolutionary process and usage patterns of the character 齐, concluding that it exhibits both orthographic and popular forms. These two variants coexisted in ancient documents, though their frequency of use varied significantly. Moreover, the dominant glyph of 齐 differed across dynasties. From the Qing Dynasty through the Republic of China era to the Peoples Republic of China, the official standardisation of 齐 underwent a developmental trajectory from 齊 to 齐, which can be categorised into three distinct phases: the incipient period, the exploratory period, and the finalisation period.