Since ancient times Nature has served Man, being the source of his life. For thousands of years people lived in harmony with environment. But with the development of civilization man’s interference with nature began to increase. Large cities with thousands of smoky industrial enterprises appear all over the world today. They pollute the air we breathe, the water we drink, the land we live in. Many cities suffer from smog. Vast forests are cut and burnt in fire. As a result some rare species of animals, birds, fish and plants disappear forever. Environmental protection is a universal concern. That is why serious measures to create a sistem of ecological security should be taken. Some progress has been already made in this direction. As many as 159 countries-members of UNO – have set up environmental protection agencies. The accident at Chernobyl nuclear power station in April 1986 caused radioactive pollution of a vast area. The international organization Greenpease is also doing much to preserve the environment. The Earth is our home. We must take care of it for next generations and ourselves.