This monograph is devoted to the activation and various transformations of saturated hydrocarbons (alkanes), i.e. reactions accompanied by the C--H and C--C bond cleavage. Alkanes are the main constituents of oil and natural gas, and consequently are the principal feedstocks for the chemical industry. On the other hand, these substances are known to be the least reactive organic compounds. Special attention is paid to the recently found alkane activations in the presence of metal complexes, which are described in more detail. In addition to the reactions of saturated hydrocarbons which are the main topic of this book, the activation of C--H bonds in arenes and even olefins and acetylenes are considered. The monograph will be useful not only for those who are interested in the activation of alkanes and other hydrocarbons by metal complexes, but also for specialists in homogeneous and heterogeneous catalysis, petrochemistry, and organometallic chemistry. Some parts of the monograph will be of interest for specialists in inorganic and organic chemistry, theoretical chemistry, biochemistry and even biology, and also for those who work in the petrochemical industry, industrial organic synthesis and biotechnology.