The book contains all the theoretical and experimental problems of the last six International Mendeleev Chemistry Olympiads 2001-2006. It is a result of a great work of a large group of scientists from different countries, whose biography data are also pre­sented in the book. The reader has a possibility to completely comprehend the system of the Mendeleev Olympiad problems , to get information about the modern directions of the development of chemical science, as well as about the people who devoted their lives to chemistry and chemistry Olympiads.