Moire method is a useful method to measure deformation and strain distribution of structures. Moire fringe patterns are analyzed quantitatively and speedy by image processing using a computer. In this paper, the theory of moire method and sampling moire method is introduced. Since the sampling moire method is useful to analyze phases of a moire fringe and a grating from one image of a grating pattern, it is possible to analyze dynamic deformation accurately. Some applications of the sampling moire method to displacement measurement of a beam, and shape and strain measurement of a rubber structure are shown.