In this paper, joint user pairing and resource allocation is investigated for improving energy efficiency of multiuser multiple-input-multiple-output (MU-MIMO) single-carrier frequency division multiple access (SC-FDMA) systems. We first formulate an optimization problem to maximize energy efficiency with the maximum transmit power constraint and restrictions of minimum rate requirements from multiple users. To reduce computational complexity, we divide the joint optimization problem into two subproblems: energy efficient power allocation and joint user pairing and resource block allocation. For these subproblems, we develop a suboptimal algorithm with low implementation complexity. Simulation results demonstrate that the proposed scheme can achieve significant energy efficiency gain compares with conventional schemes.