In the extensive air shower simulation program CORSIKA the interaction models HDPM and VENUS are available to simulate hadronic reactions of cosmic rays in the atmosphere. In a test version of CORSIKA we have implemented three other interaction models which are widely used in air shower simulations, namely SIBYLL, QGSJET, and DPMJET. A comparison of the interaction models with each other and with experimental data was performed for primary nuclei, nucleons, and mesons in the energy range from 10 1 1 to 10 1 7 eV colliding with protons and nitrogen. Some results of this comparison are presented and differences between the models with respect to their impact on the air shower development are discussed.