Abstract: In this paper, we present an algorithm for the reconstruction of piecewise linear surfaces from unorganized sample points with an improved α-shape. Alpha-shape provides a nice mathematical definition of the "shape" of a set of points, but the selection of an α value is tricky in surface reconstruction. F or solving this problem and the non-uniform distribution, we scale the α ball according to the point's density. The method discussed in this paper might be applied for surface reconstruction, and the process is fully automatic.