In this work, neutron knockout reactions of 15C on a 9Be target at energy 103 and 250 MeV/nucleon are studied. Using the Eikonal approximation of the Glauber model, total neutron removal cross sections, the stripping and diffractive cross sections as well as 14C longitudinal momentum distributions are determined in both 15C ground state and exited states of the wave function. We compared the results of our calculations with the available experimental data obtained recently. The calculated cross sections of 15C and 14C reactions, as well as the momentum distribution are in relatively good agreement with available data.