Objective To study the surgical technique of endoscopic transnasal biopsy for the diagnosis of cavernous sinus lesions.Methods Ten patients with cavernous sinus lesions were diagnosed by endoscopic transnasal biopsy.Retrospectively the clinical data of 10 patients were reviewed.Results The accuracy of diagnosis with this technique WSS 100%.Postoperative results included:5 patients with malignant tumors received radiotherapy,1 pauent with meningioma underwent yknife treatment,and 1 patient received antifungal therapy.2 patients with benign lesion and 1 patient underwent local radiotherapy were followed.Postoperative complications included:one patient with internal carotid artery injury was treated by interventional ballon occlusion and one with transient eerebrospinal leakage.Conclusion Endoscopic transrmsal biopsy is an effective.safe and mini-invssive approach for the diagnosis of cavernous sinus lesions.