The present invention relates to a method and apparatus for efficiently controlling access for system load adjustment in mobile communication systems. A method for transmitting and receiving data by a terminal including a user equipment (UE) non access stratum (NAS) and a UE access stratum (AS) includes the steps of: receiving by the UE AE, information including emergency call-related information which includes barring information by type for the emergency call, from a base station; transmitting, by the UE NAS, a service request for the emergency call to the UE AS; and determining, by the UE AS, whether to bar the service request on the basis of emergency call-related information. During an emergency call transmission, network congestion can be easily controlled by enabling various types of emergency calls to be transmitted, and enabling access to be barred information according to the situation of a communication network and types of emergency calls.