The book provides data on the most important poisonous representatives of the fauna and flora of the USSR and the toxins they produce. Issues of the ecology of poisonous animals and plants, their protection and rational use, the chemical nature and molecular structure of toxins, the mechanisms of their damaging effects and first aid measures are considered. Material is presented on the use of zoo- and phytotoxins in biology and medicine. A reference guide for university students on special topics. "Biology"