Imaging velocity interferometer system for any reflector (VISAR) is an important diagnostic tool for a variety of experiments involving laser-driven shock-wave propagation,including pulse shaping tool experiments for inertial confinement fusion research,high-pressure state equation experiments and materials characterization experiments.On the basis of conventional VISAR,an imaging VISAR has been implemented at the shenguang-Ⅲ prototype.Making use of the imaging VISAR,velocity of free surface and shock wave traveling through transparent media can be measured.The key points in designing an imaging VISAR are described in detail.Analyzing and testing the capability of the imaging VISAR indicate that the instrumen′s temporal resolution is 30 ps,spatial resolution about 10 μm,and velocity can be measured over the range from 6-45 km/s.