A data processing method when the handover or change appears between systems includes: the source data forwarding network element forwards the data to the user plane anchor network element; the user plane anchor network element forwards the data to the target side processing network element. A data processing method when the handover or change appears between systems is also provided by the present invention, which includes: the user plane anchor network element receives the message indication, transmits the data to at least one of the source data forwarding network element and the target side processing network element; the user plane anchor network element updates the route of the user plane, and transmits the data to the target side processing network element according to the updated route of the user plane. A data processing method when handover or change appears between GERAN/UTRAN systems under the Direct Tunnel solution is provided by the present invention, which can be applied to the Direct Tunnel solution.