Abstract: 【Abstract】The effective treatment of primary angle closure glaucoma (PACG) is surgery. The anterior segments of the eye can be analyzed and quantitatively measured with the ultrasound biomicroscope (UBM). Thus, the pathogenesis of PACG can be evaluated precisely, such as  pupillary block angle\|closure glaucoma,  nonpupillary angle block glaucoma or combined mechanisms. After surgery, the  peripheral iridectomy, the shape of the filtering bleb as well as the postoperative complications such as ciliary body detachment, choroidal detachment and delayed suprachoroidal hemorrhage,  can be also observed with UBM.  (Int Rev Ophthalmol, 2013, 37: 92-97)