The present invention relates to a method in which a terminal reports the results of quality measurement based on a specific reference cell from among a plurality of serving cells for the terminal in a mobile communication system using carrier aggregation. The present invention also relates to a terminal apparatus for the method. For this purpose, the terminal receives measurement configuration information from a network, performs a quality measurement in accordance with the received measurement configuration information, determines whether or not a report criterion based on a specific reference cell from among the plurality of cells for the terminal is met in accordance with the measurement result, and, if the report criterion based on the specific reference cell is met, sends a report message, including the measurement results and an indicator that indicates the specific reference cell, to the network.