A synchronization method, a communication handover method, a radio network, and a RAN node are disclosed. The interface information synchronization method includes determining whether a condition for initiating interface information update is fulfilled. Information about the S1 interface between the RAN node and the core network node, is sent. In addition, or alternatively, information about the X2 interface between the RAN node and the neighboring RAN node is sent to the neighboring RAN node if the condition for initiating interface information update fulfilled.