Objective: To evaluate the postoperative denture restoration and denture function in patients with mandibular defect reconstructed with vascularized free fibula flap. Methods: In the study, 154 patients who underwent mandibular segment resection and used vascularized free fibula flap to repair mandibular defects due to inflammation, trauma and tumor from January 2015 to December 2020 were collected. These patients had common inclusion criteria which were stable occlusal relationship before operation, segmental defects of mandibular bone caused by lesions of mandible and adjacent parts (such as floor of mouth, tongue, cheek), free fibula flap used for repair and surviving after operation. Relevant data were reviewed and situation of denture restoration was followed up. A questionnaire related to denture functional evaluation had been proposed for those who had completed the denture rehabilitation. The evaluation index of denture restoration function was assigned by expert authority to obtain the denture function score. SPSS 18.0 software was used for statistical analysis of the basic information of the patients included in the study and the denture restoration of the patients. Results: The rate of postoperative denture restoration in the patients with mandibular defects repaired by free fibula flap was 17.5%, and the rate of postoperative denture restoration in the patients with benign mandibular tumors was 25.0% (18/72), which was significantly greater than that in the patients with malignant tumors 11.0% (9/82, P < 0.05). There was no significant difference in denture function score between the patients with condylar defect and those without condylar defect in denture repair rate and denture function score (P>0.05). The functional score of implant denture was significantly greater than that of removable denture (P < 0.05). According to Brown classification, the denture function score of the patients with the defect invo-lving the anterior mandibular region was significantly greater than that of the patients without the anterior mandibular region involved (P < 0.05). The poor oral conditions, such as less amount of remaining teeth, insufficient retention strength, large mobility of soft tissue in the surgical area, poor oral vestibular groove condition became the main reason of not receiving denture restoration (37.86%). Conclusion: The denture rehabilitation of mandibular defect reconstructed with vascularized free fibula flap is closely rela-ted to pathological properties and oral conditions. The clinical outcome of implant denture has been confirmed effectively and it is a better choice for future denture restoration after mandibular reconstruction.