The Lower Permian reefs in the world are distributed in the northwestern Pangean shelf, west slope of the Ural Mountains or eastern margin of the Russian Platform, the Permian Basin of North America and other localities. They occurred mainly in the former two areas. During the earlier period of Early Permian, the reefs were predominated by Palaeoaplysina or Palaeoaplysina-Phylloid algae, but to the later time of Early Permian, the reefs were replaced by Shamovella (Tubiphytes) and bryozoans as their framebuilders. The Early Middle Permian (Qixian Stage) reefs are discovered only in the Glass Mountains of North America, Pamirs and Aerge Mountains in West China. The Late Middle Permian (Maokouan Stage) reefs are regarded as the most well-developed reefs in the world. The Permian reefs of the Guadalupe Mountains become the most classic reefs which exhibit well distinct differentiation of sedimentary facies. The Middle Permian Tunisian reefs have been studied in details. The Middle Permian reefs are characterized by the abundance of sponges, bryozoans and Shamovella (Tubiphytes) as their framebuilders, and Archaeolithoporella, Shamovella and fistuliporids as their binders. The Late Permian reefs in the world occur in the Zechstein Basin of West Europe, western marginal shelf and northern marginal shelf of the Tethys, and some terranes within the Panthalassen ocean. The Late Permian reefs are well developed in South China, which constitutes a bright spot in the distribution of the Permian reefs. These reefs are characterized by coralline sponges, including the sphinctozoans and inozoans as their framebuilders. Archaeolithoporella and Shamovella (Tubiphytes) are usually formed as encrusting and binding organisms.