Abstract: In order to obtain the real initial hydration model of cement particles,a novel shape reconstruction approach of cement particles,which integrates methods of slices-based reconstruction and multi-level partitioning of unity（MPU） implicit model,is presented.It combines the geodesic/geometric active contour（GAC） model and the active contour without edges（ACWE） model with a weight function to extract the raw contours of cement particles from a series of sample grey images by global minimization.The accurate particle contours are determined by accounting for the largest grey variance between-different classes.These 2D contours are then converted to 3D points and the normal at each sample point is estimated by plane fitting.The global shape of the 3D cement particles are reconstructed with the improved MPU method.Experimental results show that the proposed approach is not only capable of acquiring more satisfactory reconstruction results compared with other cement material reconstruction methods but also easy to implement.