Primary angle-closure glaucoma (PACG) is an independent and complex disease. According to International Society Geographical & Epidemiological Ophthalmology (ISGEO) PACG is defined as primary angle closure (PAC) with glaucomatous neuropathy, whereas a diagnosis of PAC will be given to patients without a neuropathy. This classification is simple and very useful in survey. In contrast, conventional classification of PACG by Chinese Glaucoma Association is based on anatomical predisposition, such as peripheral iridocorneal apposition/adhesions, and functional sub-stages, which is more clinical usefulness. The difference of PACG classification system between Chinese Glaucoma Association and ISGEO appears to hinder the communication and cooperation between Chinese and international colleague. In this article, we attempted to review classifications and analyze the epidemiological characteristics of PACG under these two systems. It is obvious that the continuing effects to establish a rational and standardized classification system of PACG will greatly promote and benefit glaucoma research and clinical practice for both international and domestic ophthalmic community.