The latest progress in olefin metathesis reaction, the key areas of ring-closing olefin metathesis reaction (RCM) and cross-metathesis review. Numerous display olefin metathesis reaction, the catalytic activity of the complexes, the definition of the recently developed [MO] and [Ru catalyst system has been proven very effective, tolerance polyfunctional. The medium or macrocyclizations, of RCM organizational aspects of peptide chemistry, series ring-opening/ring-closing reaction, and RCM-mediated recombination. Substrates, such as have been discussed in combination in the polymer a change in the form. No metathesis and ring-opening cross-complex decomposition also included.