Three-dimensional (3D) T2 mapping techniques enables quantitative detection of edematous tissue with whole heart coverage. However, the intrinsically long scan time limits its clinical application. In this study an accelerated 3D T2 mapping sequence was developed based on low-rank plus sparsity reconstruction. Both retrospective and prospective experiments were performed to evaluate the accuracy and precision of the proposed method. Achieved image quality was comparable with 4 times acceleration. Homogeneous whole left ventricular T2 map can be acquired in single breath-hold with resolution of 2×2×5 mm3.