In this study, neutron-emission spectra produced by (pxn) reactions for some spallation neutron target nuclei such as (65)Cu, (204.206.207.208)Pb, (209)Bi, (232)Th and (238)U have been calculated by a proton beam up to 140 MeV. Multiple pre-equilibrium mean free path constants from internal transition for (204,208)Pb (p, xn) neutron emission spectra have been investigated. In the calculations, pre-equilibrium effects were calculated by using new evaluated hybrid model and geometry dependent hybrid model, full exciton model and cascade exciton model. The reaction equilibrium component was calculated by Weisskopf-Evving model. The obtained results have been discussed and compared with the available experimental data and found agreement with each other. (C) 2009 Elsevier Ltd. All rights reserved.