A method for controlling ejector capacity in a vapour compression system (1) is disclosed. A parameter value being representative for a flow rate of liquid refrigerant from the evaporator(s) (8, 10) and into a return pipe (12, 13) is obtained, and the capacity of the ejector(s) (6) is adjusted based on the obtained parameter value. Ejector capacity may be shifted between low pressure ejectors (liquid ejectors) (6a, 6b, 6c, 6d) and high pressure ejectors (gas ejectors) (6e, 6f).