Аннотация:The review is devoted to an analysis of the metathesis of lower olefins on molybdenum-containing heterogeneous catalysts. Individual aspects of the cross-metathesis reaction are analyzed: the main industrial processes based on metathesis are described, the kinetic and thermodynamic issues of the reaction are considered, and the mechanisms of individual stages are discussed. The relationship between the structure of catalysts and their catalytic activity is demonstrated. Particular attention in this review is given to methods for improving catalytic systems based on molybdenum oxide.