This paper describes a method for sharing history-based parametric modeling data of free-form shape with different CAD systems and storing them in a form of text information. Parametric is quite effective, however, parametric modeling data is valid only in the exact same CAD systems because these data depends deeply on the programming algorithms and system tuning parameters such as tolerance. In the method, guidelines to decompose a conventional CAD operation into appropriate programming units (software components), which can be sharable among different CAD systems, are shown. B-spline surface generation system is developed to verify the effectiveness.