This paper proposes a new method for inverse synthetic aperture radar (ISAR) imaging of multiple targets based on sparse representations. The proposed method includes three steps: (1) coarse estimation of the radial velocities of the targets using Radon transform; (2) signal separation of different targets using sparse representation (SR) method; (3) refocusing of each targets using traditional range-Doppler algorithm. The effectiveness of the proposed method is verified using real ISAR data.