A method and device are disclosed for a remote User Equipment (UE) to support UE-to-Network relay communication. The remote UE establishes a PC5 connection with a first relay UE for a relay communication with a first network node. The remote UE also performs a Radio Resource Control (RRC) connection establishment procedure with the first network node via the first relay UE. Furthermore, the remote UE transmits a first RRC message to a second network node via a second relay UE for requesting RRC connection re-establishment, wherein the first RRC message includes a first Cell Radio Network Temporary Identifier (C-RNTI) of the remote UE. Also, the remote UE receives a second RRC message from the second network node via the second relay UE for re-establishing a RRC connection between the second network node and the remote UE, wherein the second RRC message includes a second C-RNTI of the remote UE.