Objective: To assess the clinical outcomes of fenestration decompression and cyst plug in the treatment of jaw cysts. Methods: 35 patients with large jaw cysts(14 cysts in maxilla, 31 cysts in mandible) were retrospectively reviewed.After fenestration and marsupialization, cystic substance was sucked and the remaining cyst wall was kept. A cyst plug was made to ensure the continuous drainage of the cystic fluid and keep the cystic intra-cavity clean. Regular examination and follow-up visits were made at 1,3,6,9 and 12 months after surgery. Results: At 12-month after surgery, maxium cystic diameter reduced less than 50% in 6 cases, while in other 29 cases cystic diameter reduced more than 50% or cystic cavity regenerated. Conclusion: Fenestration decompression is a simple and effective treatment of the jaw cysts.