Abstract: Objective:?To explore the distribution characteristics of primary cilia in tooth development and further reveale the correlation between primary cilia and tooth development. Methods:?Hematoxylin-eosin (HE) staining and immunofluorescence staining of histological sections were used to observe the distribution characteristics of primary cilia in the bud, cap, and bell stages of mouse tooth germ development, as well as the matrix secretion period after birth. Results:?The primary cilia were widely distributed in the bud stage, while rarely observed in the basement membrane of the epithelium; cells with primary cilia in inner enamel epithelium gradually increased at the cap and bell stages; In one-week mouse tooth germs, all ameloblasts in the secretory phase had primary cilia, and the location of primary cilia in these cells was switched to the matrix secretion side, while there are fewer primary cilia in the odontoblasts during the same period. Conclusions:?Primary cilia have different distribution characteristics at different stages of tooth germ development; the appearance and location of primary cilia in ameloblasts are closely related to the differentiation of ameloblasts; primary cilia are dynamically involved in the whole process of mouse tooth development.