The present invention relates to a method for processing information between mobile communication systems in order to prevent the degradation of user-experienced performance when different types of mobile communication networks are used. The method for processing information at user equipment (UE) to improve user-experienced performance of a mobile communication system includes performing a data communication through a first network and receiving, from a policy server, a routing policy including a validity condition which is information about a condition of designating a UE status for handover. The method further includes, in the handover, if a searched second network satisfies the validity condition, performing the data communication through the second network. Accordingly, a network for data transmission can be selected using a routing policy created in consideration of a UE status or a network status, thereby enhancing user-experienced performance.