Abstract: For the purpose of surface reconstruction from serial sectional contours,the spatial distribution characteristics of complicated serial sectional contours are analyzed,and an efficient algorithm is proposed for true three-dimensional TIN modelling concerning the reference plane.Starting with a seed edge,the new point of triangle is selected based on the local flatness of surface and minimum-weight triangulation.Not only the shape of triangle patch but also the spatial relationship between triangle and neighbor points are considered in the triangulation criterion.This method guarantees to produce non self-intersected surface and the reconstructed surfaces are then close to the actual surface.Experiment is carried out with multi-layer reflected wave data from three-dimensional seismic exploration.