The differentiation of Chinese characters is accompanied by the development of Chinese writing and is one of the manifestations of the adaptation of Chinese characters to record Chinese language. There are not only macroscopic and microscopic reasons, but also textual factors and linguistic factors for the differentiation of Chinese characters. To record Chinese accurately and clearly is the radical cause of character differentiation. The emergence of specific differentiated characters has its own influencing factors. It is particularly important to investigate the lexical items and their properties recorded by the mother characters to uncover the specific causes of the differentiation. In terms of lexical items, the degree of meaning clarity, semantic alienation and that of prominence and emphasis are the important factors that affect whether the lexical items represented by the mother character can obtain graphic marks independently, which is helpful to explore the internal motivation of Chinese character differentiation.