Abstract: This paper is concerned with the high temperature steam passivation processing of the Y-15 equilibrium catalyst under analogue condition at different temperatures, pressures and periods.The passivating effect and properties are compared with the equilibruium catalyst passivated by the antimony passivating agent.The result shows that the productivity of hydrogen and coke decreases greatly and the productivity of gasoline goes up a little after high temperature steam passivation. The micro-activity index drops down slightly. Steam passivation effect is better than that of antimony passivation agent in both activity and selectivity. As a result, passivation with steam can effectively control the dehydrogen and coke forming reactions which are caused by nickle deposition on the equlibrium catalyst,while its activity has no obvious change.