The present invention discloses a shape comparison apparatus and method based on contour decomposition and correspondence. The apparatus comprises a polygonal approximation unit for approximating an image object contour as a polygon, namely representing the image object contour into an ordered contour primitive sequence; an attribute generation unit for calculating attribute value for contour primitive and contour primitive composition; and a comparison unit for establishing correspondence of polygons and hence calculating similarity between contours. Preferably, the apparatus further comprises an image object contour extraction unit for extracting, in the case the input into the apparatus is an image object rather than an image object contour, an image object contour of an image object inputted into the apparatus.