Since the 21th, with the upgrading of the strategic position of rare earth resource, more and more attention has been paid to the changes of supply- and- demand and price of REE. Then, exploration for REE deposits is active all over the world. Ion- adsorption type REE deposits have become a hot topic of recent studies and exploration, because they have large resources of HREEs, and relatively low mining and processing cost using ion exchange with a dilute electrolyte solution. The deposits mainly distributed in South China. They have been exploited for more than 40 years and made significant contributions to the development of the global rare earth industry. In recent years, a number of mineral resources were verified in Jiangxi, Guangxi and Yuannan provinces. The distribution of such deposits has expanded from hilly areas to high altitude and latitude in south China, also from subtropics to tropical climates such as Vietnam, Myanmar and Thailand. Our research on the deposits continues to enrich the understandings, that are, multi- subtypes (eg.ion- adsorption La deposit, ion- adsorption Eu deposit, ion- adsorption Dy deposit and so on), multi- lithology (eg. granitic rocks, pyroclastic rocks, and metamorphic rock), multi- periods, multi- stratigraphic horizon, multi- metallogenic model, multi- prospecting marker (eg. chemical index of alteration and loss on ignition), multi- REE source (eg. magmatic crystallization and hydrothermal alteration), multi- geological occurrence (intrusive or extrusive rocks), high latitude, high altitude and large depth. Furthermore, the geological characteristics of weathering crust in the subtropic and tropic, the difference between weathered granite, rhyolite and meta tuffite, and the migration and enrichment of REEs from parent rock to orebody to rare earth product (REE carbonate) have been studied. In a word, ion- adsorption REE deposits in south China are superior to those in other countries in terms of size, grade and REE compositions. China is still unable to get rid of the situation of environmental pollution and excessive consumption of REE resources for a long time. Searching for the deposits with great economic value is an important prospecting direction in the future.