Method and system for updating air interface keys

A method for updating air interface keys is disclosed in the present invention. The method includes that: after a serving radio network controller has made a decision to implement relocation, the serving radio network controller sends key information to a target radio network controller directly or via a core network node; or the serving radio network controller informs the core network node that the core network node should send the key information to the target radio network controller. A system for updating air interface keys is also disclosed in the present invention, which includes a serving radio network controller and a target radio network controller; and the serving radio network controller is configured to, after making a decision to implement relocation, send key information to the target radio network controller directly or via a core network node; or notify the core network node to send the key information. The present invention can improve the safety of the system.