The resent researches on primary angle closure glaucoma (PACG) in China were reviewed. The prevalence of PACG (0.41%) in chinese is between the Caucasian and Eskimos, and chronic type is the dominant type in PACG. However, with the economic development and medical care improvements, the prevalence condition of PACG may change; several researches discovered that the mechanism of PACG, especially the chronic type, is not only because of pupil-blocking but also closely related to the mechanism of crowding of peripheral iris and the anterior location of the ciliary body. We supposed that PACG can be divided into several subtypes based on this machnism. Also, we believe that the use of ultrasound biomicroscopy (UBM) and ophthalmic laser in China has promoted the research of PACG and improved the level of prevention and treatment of PACG. Eye Science 1997; 13 : 120- 124. The resent researches on primary angle closure glaucoma (PACG) in China were reviewed. The prevalence of PACG (0.41%) in chinese is between the Caucasian and Eskimos, and chronic type is the dominant type in PACG. However, with the economic development and medical care improvements, the prevalence condition of PACG may change; several researches discovered that the mechanism of PACG, especially the chronic type, is not only because of pupil-blocking but also closely related to the mechanism of crowding of peripheral iris and the anterior location of the ciliary body. We supposed that PACG can be divided into several subtypes based on this machnism. Also, we believe that the use of ultrasound biomicroscopy (UBM) and ophthalmic laser in China has promoted the research of PACG and improved the level of prevention and treatment of PACG. Eye Science 1997; 13: 120-124.