Objective To explore the clinical application of free anterolateral flaps in reconstruction of postoperative defects of maxillary sinus.Methods The postoperative defects of maxillary sinus were reconstructed using free anterolateral flaps in 17 cases.Results Among the 17 cases,2 cases occurred vascula crises,1 case occurred flap necrosis,5 cases had early local complications.After 3 months to 4 years follow-up,the appearance and functions on the head and heck area turned to be normal in 10 cases.No severe complication occurred in both donor and recipient site.2 patients survived with tumor and 7 patients died of local recurrence,cervical lymphatic metastasis and distant metastasis.Conclusion Anterolateral flap is easy to shape and has less complications of donor site.It is useful in the reconstruction of postoperative defects of head and neck tumor.