We present a simple pairwise matching method for 3D fragment reassembly that uses boundary curves and concave-convex patches to accelerate and optimize the matching. Given the boundary curves of two fracture surfaces that completely or partially coincide, we can quickly exclude the fracture surface pairs with low boundary curve similarities, which can substantially reduce the computational cost of the subsequent patch matching, where we extract and delineate concave-convex patches of the selected fracture surfaces. A modified iterative closest point algorithm is applied on these concave-convex patches to refine the alignment. Finally, we determine the matched 3D fragments according to the overlap ratio of their fracture surfaces. The results of experiments on real-world examples demonstrate that our proposed algorithm is both accurate and efficient. INDEX TERMS Boundary curve, concave-convex patch, fracture surface, fragment matching.