New development of numerical methods for contact analysis with JIFEX software The finite element software JIFEX is developed with the application-oriented concept for complex structures of general purpose engineering. We describe the software integration into the finite element analysis, structural design optimization, and into the pre- and post-processing, implemented on the advanced platform Windows 95/NT. The three-dimensional contact analysis is one of the most important features. In this paper, we use a combined parametric quadratic programming and iteration method to avoid the difficulties of unknown slip direction of tangential displacement at contact point. The numerical examples are presented together with a introduction into the application-oriented software JIFEX.