Abstract: Objective: To evaluate the decompression combined with calcium sulfate with clinical curative effect of the treatment of jaw cysts. Methods: From 2009 August -2013 year in August in our hospital were the large jaw cystic lesions in patients with a total of 70 cases, all patients were informed of the pros and cons of communication before operation, and the risk in patients with various kinds of treatment plans, according to the wishes of patients, divided into the observation group and the control group, the observation group of 35 cases received conservative treatment, I window decompression, the cysts reduced obviously after II small cyst curettage and calcium sulfate biological material filling operation, the control group of 35 cases, treated with traditional jaw cyst curettage, and calcium sulfate biological material filling, observed and compared two groups of patients with operation time, bleeding volume during operation, postoperative pain, postoperative, infections, cystic cavity size, degree of hyperplasia of bone thickness and bone density measurements, the incidence of recurrence and neuropathic complications were compared between the two groups at the same time. Results: The two groups of patients with operation time, intraoperative bleeding volume, postoperative pain and postoperative infection rate of phase difference was statistically significant (P<0.05); the two groups of patients after 6 months the index operation after 3 months were significantly improved, the observation group of patients after 3 months and after 6 month sac cavity was reduced in value, postoperative bone hyperplasia thickness value, postoperative bone density measurements were superior to the control group, the difference was statistically significant (P<0.05). All patients were followed up for 12 to 24 months, the control group 1 patients relapse, the observation group without recurrence, two groups of patients relapse rate difference does not have statistical significance (P<0.05). Conclusion: The clinical effect of large cystic lesions of the jaw is good with open window decompression, and it is worth to be popularized in clinic.