A communication control method in a mobile communication system, wherein each of a plurality of cell sets a CSS that is applied in common to all UEs 100 within the corresponding cell, and information associated with system information (an SIB 13) that is necessary for the reception of the MBMS control information is arranged in the CSS. The communication control method includes a step of simultaneously performing, by a UE 100, communication with a first cell operating as a main cell in which blind decoding for the CSS is required, and communication with a second cell operating as a subordinate cell other than the main cell; and a step of transmitting, by the UE 100, to the first cell, a main cell change request for changing the main cell from the first cell to the second cell.