ISAR imaging of high speed moving target has drawn extensive attention for its practical applications. However, the imaging quality is affected significantly by the phase modulation induced by high speed motion. To suppress the influences of high speed motion efficiently, a novel ISAR imaging method for high speed moving target based on the parametric sparse representation is proposed. First, the echo signal is sparse represented via designing a flexible parametric sensing matrix according to high speed motion. Subsequently, the sensing matrix is optimized after adaptive computation, during which the target velocity estimation is involved. Finally, a clear ISAR image can be reconstructed with less sampling data and without the motion compensation in conventional ISAR imaging. Compared to the existing method based on compressed sensing (CS), the proposed method possesses lower computational complexity and better robustness.