A study has been made of the influence of the composition of the catalytic system PdCl2-CuCl2-Cu(OAc)-Mn(OAc)2 and also temperature and partial CO pressure on the total yield of products and the selectivity of the oxidative carbonylation of propylene. Factors making it possible to increase appreciably the selectivity of the reaction with respect to methyl isobutyrate, methyl crotonate and dimethyl-2-methyl succinate have been established. The mechanism of the reaction has been analysed from the viewpoint of process regioselectivity. A comparison of data obtained in a study of the oxidative carbonylation of propylene and styrene demonstrated the basic similarity of the key stages of the mechanism in these processes and also made it possible to explain their results from common viewpoints.