A method and user equipment for reporting a measurement result in carrier aggregation are provided. The method for reporting the measurement result of carrier aggregation includes: the user equipment reporting a measurement report which carries measurement results of part of or all of component carriers in a same carrier-aggregation cell. With the invention, the problem that a network cannot correctly evaluate the channel quality of a carrier-aggregation cell because the network can only acquire the measurement result on a single component carrier is resolved. The present invention further can assure a service quality when the UE performs handover between cells of carrier aggregation, and satisfy good performance of UE mobility between carrier-aggregation cells.