Abstract: Objective:To observe the effect of cell primary cilia ablation in femur perichondrium on growth plate development of long bone. Methods:Twenty male 4-week-old wild-type mice were randomly divided into control group and experimental group. For the experimental group, chloral hydrated (CH) (0.01 mL/g) was topically injected outside the femur growth plate every 2 days in mice, while the same amount of saline was given in the control group. After 4 weeks of continuous injection, mice were sacrificed. Micro-CT scan was used to analyze the mineralization of subchondral bone, and the incidence of primary cilia and growth plate cell morphology was observed by histological slicing. Results:In the experimental group, the presence of primary cilia in the perichondrium was decreased and the mineralization of subchondral bone was reduced. The formation of primary cilia in the femoral perichondrium was inhibited by CH, which could hinder the arrangement and function of the growth plate chondrocytes, disarrange the structure of the growth plate and decrease the number of bone trabeculae under the growth plate. Immunofluorence staining showed that the incidence of primary cilia in the perichondrium was decreased in the experimental group (P＜0.001) and the secretion of type II collagen of the growth plate chondrocytes was also decreased. Conclusions:Primary cilia in perichondrium was involved in the development of cartilage and bone of the growth plate.