Thallium is a high toxic element, and the enrichment of thallium in environments is very dangerous to plants and animals as well as human beings. In this article, it is made an extensive review on the major progresses been made on thallium environmental geochemistry, such as the distribution and migration of thallium in rocks and ores, soils, waters and plants and animals; and the primary countermeasures to prevent and cure thallium pollution are proposed.