AIM: To compare the effectiveness of diode transscleral cyclophotocoagulation(CPC)and transscleral cyclocryotherapy(CCT)for the intraocular pressure(IOP)control and postoperative complications of absolute glaucoma. METHODS: This was a prospective case observation study. Totally 85 cases with absolute glaucoma which were admitted by Tianjin Eye Hospital were randomly assigned in 2 groups to receive either CPC or CCT. IOP, the numbers of anti-glaucoma medication, inflammatory reaction of anterior segment and postoperative ocular pain which was evaluated by Visual Analogue Scale(VAS)in two groups were recorded at eight points in time: the day before surgery and 1d, 3d, 1wk, 2wk, 1mo, 3mo and 6mo after surgery. The generalized estimated equation was used to compare all the indexes before and after operation and the difference of success rate between the two surgical methods. RESULTS: Compared with CPC group, IOP of CCT group decreased less than that before surgery at 1, 3d, 1, 2wk, 1mo after surgery, VAS score decreased less than that before surgery at 3d, 1, 2wk, 1mo after surgery, and the number of anti-glaucoma drugs decreased less than that before surgery at 1, 3d, 1, 2wk after surgery(P<0.05). Compared with CPC group, the complete success rate of CCT group was higher than that at 1d after surgery at 3d, 1, 2wk, 1, 3, 6mo after operation, but only the difference of 3, 6mo after surgery was statistically significant(P<0.05). Compared with CPC group, anterior chamber flash grade of CCT group increased more than that before surgery at 3d, 1, 2wk, 1mo after surgery, conjunctival congestion grade increased more than that before surgery at 1, 3d, 1, 2wk after surgery, corneal edema grade increased more than that before surgery at 3d, 1, 2wk, 1mo after surgery(P<0.05).CONCLUSION: Compared with CPC, the rate of IOP reduction after CCT was slower, the inflammatory reaction of anterior segment and discomfort of eyeball were more severe and lasted longer. Therefore, the duration of anti-inflammatory drugs and anti-glaucoma medications should be extended after the surgery.