This paper focuses on the multi-user MIMO resource scheduling of LTE-Advanced system with carrier aggregation. With the special function of a UE's primary component carrier (PCC), the original proportional fair (PF) scheduling scheme can result in invalid user groups for multi-user MIMO transmission, making UEs of the user group can not be transmitted. A multi-user MIMO resource scheduling scheme for carrier aggregation scenario (RSM-CA) is proposed. Compared to PF, RSM-CA guarantees the resource on the PCC of a UE is primarily allocated to the UE, making sure all user groups are valid. Furthermore, frequency selective diversity, which is specific for carrier aggregation scenario, is exploit in RSM-CA to maximize the system throughput. According to the system level simulations of downlink LTE-A, RSM-CA can achieve better system throughput than the original PF scheduling scheme.