The determination of the position and attitude of the strength cracking of the arch dam has been an advanced research in dam engineering. As a complicated statically indeterminate system, the computation effort on the dam and its foundation is huge. How to decrease the computation scale and improve the computation efficiency was an important problem in numerical analysis of arch dam. With currently computer facilities, the most possible area of the cracking was first located and its elements were used as the locating elements. The locating elements were further divided into smaller elements, from which the accurate position of the cracks were determined. New nodes appeared after the division of the locating elements and these new nodes were attached to the nodes of initial elements by nodes stiffness attaching method. In that case, the element stiffness matrix was replaced with the stiffness matrix of attached elements; the stiffness matrix and the numerical methods of the main program could be kept the same. Since the method of location attaching was just a unit of the main program, the computation scale was decreased and efficiency was improved. The method was used in an example engineering problem and proved to be able to determine the position and attitude of the strength cracking. The method is found to be very useful since the cracking can be rationally estimated in practice..
