In order to compress three-dimensional data (120) with a high compression rate without degrading resolution or precision, coupling coefficients are calculated from input three-dimensional data and a basic three-dimensional data group obtained from a plurality of objects, and outputted as compression data (130). More specifically, the three-dimensional data (120) is inputted to a corresponding point determining means (101) where composition object three-dimensional data (103) is prepared by relating the apex of the three-dimensional data (120) to the apex of reference three-dimensional data (111) serving as a reference for determining correspondence relation of apex. A coefficient calculation means (102) calculates coupling coefficients for compounding the composition object three-dimensional data (103) by coupling the basic three-dimensional data group (112) used for compounding the three-dimensional data, and outputs the calculated coupling coefficients as the compression data (130) of the three-dimensional data (120).