To investigate the microsurgical management of cranionasal tumors and the method of the reconstruction of the skull base. Methods From June 2005 to October 2007, 20 patients with cranionasal tumor were treated. There were 10 males and 10 females, aged between 13 and 77 years (median 49 years). The disease course was 2 months to 13 years.The cranionasal tumors, proved by MRI and CT scans, located in the anterior skull base, paranasal sinus, nasal and/or orbit cavity. And their cl inical presentations were l isted as follows: dysosphresia in 14 patients, headache in 11 patients, nasal obstruction in 9 patients, epistaxis in 8 patients, visual disorder in 4 patients, exophthalmos in 4 patients and conscious disturbance in 2 patients. All 20 patients underwent transbasal surgery combined with transnasal surgery, and tumors were resected by one-stage operation. The skull base was reconstructed by surgical technique “Pull Down Sandwich” with pedicle periosteum flap. Results Tumors were resected by one-stage operation, and the anterior skull bases were reconstructed. Pathological examination showed 8 cases of mal ignant tumors and 12 cases of benign tumors. The total surgical excision was complete in 16 patients, and 4 patients with subtotal excision. There was no operative death. Eighteen patients were followed up 3 months to 2 years and 6 months. Transient cerebrospinal fluid rhinorrhea was found in 2 cases which were cured by lumbar drainage. And recurrence of tumor was observed in 5 patients 3 months to 2 years after operation. Conclusion Microsurgical operation via subfrontal approach assisted bytransnasal endoscopy is an effective method in management of cranionasal tumors, with the advantages of econstruction of the skull base with pedicle periosteum flap or “Pull Down Sandwich” and low compl ication rate.