A temporal series digital image correlation method (TSDICM) for dynamic characteristic measurement of mechanical system is presented, which is based on highspeed imaging technique and the tracking method of digital speckle correl a tion using the sequential dynamical speckle patterns. This method has less limit ation to the surface quality of the test specimen, and also it is wholly noncont act, simple, precise, as well as adjustable to ranges of frequencies and displac ements. A free vibration test of a diesel engine is conducted and the dynamic vi bration images are captured by a highspeed CMOS camera. TSDICM coded by VC++is subsequently used to obtain the displacement signal. The FFT spectrum analysis i s performed to identify the modal parameters. Experimental results agree well wi th the electromotive and the FEM values.