In this paper, we deal with sharing of a resource block (RB) which is the basic resource allocation unit for scheduling in 3^rd-generation partnership project long term evolution (3GPP-LTE) system. In 3GPP-LTE system, a scheduler of evolved node-B (eNB) allocates respectively one or more RBs to user-equipments (UEs) considered, considering their requests, their channel qualities, and the resource availability. In the case of constant-rate service (i.e., the real-time service), some of RBs may not be fully utilized, depending on the channel quality. Especially, in the case of multiple-input multiple-output (MIMO) multiplexing, the degree of resource wastage may become much severer since a much less amount of the resource may be required for the same data rate. In this paper, we introduce the concept of RB sharing where one RB can be shared by multiple UEs depending on their respective required rates and the corresponding channel qualities. Through computer simulations, we evaluate the average sum rates for both cases of RB sharing and non-sharing. From simulation results, we see that the RB sharing scheme can achieve much greater sum rate as compared to the non-sharing one.