An ejector cycle system with a refrigerant cycle through which refrigerant flows includes an ejector disposed downstream of a radiator, a first evaporator that evaporates refrigerant flowing out of the ejector, a throttling unit located in a branch passage and depressurizes refrigerant to adjust a flow rate of refrigerant, and a second evaporator located downstream of the throttling unit. In the ejector cycle system, a flow ratio adjusting means adjusts a flow ratio between a first refrigerant flow amount depressurized and expanded in a nozzle portion of the ejector and a second refrigerant flow amount drawn into a refrigerant suction port of the ejector, based on a physical quantity related to at least one of a state of refrigerant in the refrigerant cycle, a temperature of a space to be cooled by the first and second evaporators, and an ambient temperature of the space.