The invention discloses a method for transmitting a START value. A radio resource control (RRC) message is used to transmit a START value to a radio access network (RAN), and further the RAN transmits the START value to a core network (CN) through a radio access network application part (eRANAP) message. The invention also discloses a system for transmitting the START value. The method and the system for transmitting a START value of the invention can realize the transmission of the START value to the core network (CN) by user equipment (UE), and solves the problem that the START value fails to be sent to the core network (CN) in an LTE/SAE (long term evolution research project/system architecture evolution) system in the prior art.