In this paper we identity the hazard using HAZOP study for ATSRX which is a subsystem of the ATP system, and we study a safety management method for the mitigation of the risk to the acceptable level. ATSRX is a device that make a train which has a ATP system operate in ATS line. For this ATSRX send a induction signal with ATS system to vehicle controller. Thus ATSRX can be said a safety equipment that makes a train operate safely. In order to identify the hazard for the internal faults in ATSRX system, we employ HAZOP study method which is recommended as hazard identification in IEC 62278, RAMS requirements in railway signal, and also it provide the detail activity in IEC 61882. Thus, in this paper we perform HAZOP study based on ATSRX related standards and using the assessment of the identified hazard we study a method to guarantee the system safety through the change of the design to mitigate the risk to the acceptable level.