Abstract: To find effective and intuitive ways of modeling with freeform feature，freeform feature and freeform feature definition points are parameterized in this paper，a new method of creating freeform feature with wrapping parameters and constraints is presented.Mapping from numerical parameters to geometry is defined in the definition of freeform feature.Feature definition points are picked up on a trajectory，and a cross-section is built on each points，then skinning and sweeping operation are applied on these cross-section，as a result freeform feature fitting seamlessly to the target surface is built.