In recent years, gas injection as a method of producing plastic components has become one of the most important special processes in the field of injection moldinq. The advantages of this technology are considerably less weight, a better surface quality and shorter cycle times, as compared to conventional injection molding. With the gas injection process, modem fiber reinforced composites are increasingly used, in order to substitute complex metal and alurninium components. The orientation of the fiber as well as a homogenous distribution are important for the strength of the components. In practice however, the gas injection of fiber reinforced composites is still a problem, because it is extremely difficult to calculate a homogenous distribution of the fiber and thus the quality of the components in advance. Numerous preliminary studies show that characteristics calculated by simulation software are often very different from the production results. It is thus the aim of this project, to newly determine the parameters for calculating the fiber behaviour and, to optimlze the injection behaviour of dlfferent thermoplastics wit-h different fiber contents and fiber lengths by means of a representative test mold. In order to achieve this, the influence of various parameters such as injection speed, gas delay time, gas pressure, melt and mold wall temperature will be in-tensively researched and than compared with the parameters of conventional injection molding. The results will be shown in a demand cataloque and made accessible to the users in the form of a calculation handbook, which will enable them to make first evaluations of the fiber distribution and orientation. The results of this project can drastically increase the productivity in the plastics industry regarding the product safety as well as the increasing application possibilities and processability of the fiber reinforced composites.