Based on computer-aided geometric design, the surface was reconstructed according to the given data points by means of non-uniform rational B-spline technique. With the aim of finding an optimum surface that meets the architectural intent data points, an adjustment method was presented, which takes minimum structural deformation under gravity as the objective function and data point's position as design variables. Gradient method was employed to modify the free form surface by adjusting design variables. The surface shape was modified iteratively according to data points' changes. The approach has been implemented into two projects and the feasibility of the approach was demonstrated.