In order to investigate the structural integrity of large scale structures, the prediction of the crack path is very important. For this reason, a step-by-step finite element approach has been proposed by one of the authors, Sumi, in which a cracked domain must be remeshed by an automatic mesh generator as the crack propagates in thedomainlm. In this approach, the modified quadtree algorithm is used for automatic mesh generation. One of the problem of this method is that it is difficult to generate mesh near the boundary and therefore reliable mesh generation is sometimes not possible. In this paper, the automatic quadrilateral mesh generation based on the pavingmethod is developed for the crack propagation analysis. By the developed mesh generator, completely automatic simulation and reliable analysis are possible. Also, a method for automatic choice of the increment size of the crack propagation in each step is proposed in this paper. In this method, proper increment size is first selected based on the numerical data from the computational experiences by authors. Furthermore, if the computed error of K _II K _I exceeds the allowable limit specified by the user, re-analysis of the previous step is automaticaly carried out by decreasing the increment size so that the crack path prediction can be performed accurately.