To study the role of equilibrium and pre-equilibrium emissions of the nuclear particle(s) on the excitation functions in α + 55Mn system, an experiment has been performed using an alpha particle from 10MeV-200MeV energy range. This study is aimed to compare the correlation between the theoretical and experimental excitation functions of alpha-particle-induced reactions on manganese. The theoretical calculations have been calculated using computer code of TALYS 1.95 / and COMPLET then compared with the existing experimental EXFOR data base for the same system.The analysis indicated that at higher energy points the pure compound nucleus calculated to re produce the experimental data taken from EXFOR data base at beam energies at the given energy range and reviled significant contributions from pre-equilibrium emissions. As the suggested data were analysed, a summation of both equilibrium and pre-equilibrium emissions is needed to reproduce the present experimental data in the considered energy range. In the high-energy range, equilibrium excitation functions are calculated as a function of the normalized projectile energy. Generally, the graphs were in good agreement with the values of experimental excitation functions in the selected energy range of alpha particle
