Objective: To observe and analyze the changes of anterior segment and refractive state in patients with chronic angle closure glaucoma after trabeculectomy. Methods: It was a prospective study. A total of 20 cases with 20 eyes that have met the inclusion criteria undergoing trabeculectomy were collected. The diopter of spherical power,corneal curvature, axial length (AL) and anterior chamber depth (ACD) were measured before the surgery and 1 week, 1 month, and 3 months after the surgery respectively. Results: There was significant difference (P<0.05)for the diopter of spherical power before and 1 week after the trabeculectomy, the difference was (?1.20±0.55) D.After 1 month and 3 months, the diopter of spherical power was not statistically significant (P>0.05). The corneal curvature in the vertical direction was (44.89±1.20) D, (45.72±1.54) D, (45.65±1.35) before, 1 week and 1 month after operation. The corneal curvature in the vertical direction increased significantly at 1 week and 1 month after operation (P<0.05), and there was no significant difference (P>0.05) after 3 months. The preoperative mean ocular axis length (22.49±0.43 mm) and mean anterior chamber depth (2.75±0.45 mm) compared with postoperative mean ocular axis length (21.60±0.59 mm) and mean anterior chamber depth (2.25±0.34 mm) were statistically significant (P<0.01). Comparing 1 month and 3 months after operation, there was no significant difference in the depth of the anterior chamber and the length of the eye axis (P>0.05).Conclusion: In the early stage after trabeculectomy (1 month after operation), the diopter of spherical power can be increased. The ACD became shallower, the eye axis became shorter, and the curvature of vertical direction increased resulting in myopic drift,which affected postoperative visual acuity. Over time (3 months after operation), the anterior chamber deepened,the axial length gradually increased, the vertical astigmatism and myopia drift degree gradually decreased, the anterior segment and refractive changes gradually stabilized, and the postoperative visual acuity gradually recovered.