Disclosed is a method for producing ethylene and propylene from a hydrocarbon feedstock by catalytic conversion, which comprises contacting, in a reactor, a hydrocarbon feedstock comprising 20% by weight or more, based on the weight of the hydrocarbon feedstock, of at least one C4-C12 olefin with a zeolite-containing catalyst, wherein the zeolite in the zeolite-containing catalyst satisfies the following requirements: (1) the zeolite is an intermediate pore size zeolite having a pore size of from 5 to 6.5 Å, (2) the zeolite contains substantially no proton, (3) the zeolite contains at least one metal selected from the group consisting of metals belonging to group IB of the periodic table, and (4) the zeolite has an SiO2/Al2O3 molar ratio of from 200 to 5,000, to effect a catalytic conversion reaction of the hydrocarbon feedstock, thereby obtaining a reaction mixture containing ethylene and propylene; and separating the ethylene and propylene from the reaction mixture. In the method of the present invention, the zeolite-containing catalyst has high resistance to deactivation and, thus, ethylene and propylene can be stably produced in high yield for a prolonged period of time.