The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for operating fast random access procedure in a wireless communication system, the method comprising: starting a Random Access Response (RAR) reception procedure by transmitting a Random Access Preamble (RAP) to an e-NodeB (eNB); receiving, from the eNB, an indicator indicating that the UE check a condition for whether the UE stops the RAR reception procedure or not, checking whether the condition is met or not; and stopping RAR reception procedure if the condition is met.