A theoretical model to simulate the laser induced plasma (LIP) expansion with chemical kinetics has been developed for a Ti target. Our attention has been also focused on the influence of initial conditions on the plume expansion. In particular, changing the initial speed, temperature, pressure and plume extension, the speed of expansion and the width of the time of flight (TOE) peak change. A systematic study of the effect of all these parameters on the plume expansion can lead to a method that allows the determination of initial conditions of the expansion, which are not available experimentally because of the delay necessary to trigger the measure apparatus with the laser pulse. (C) 2002 Elsevier Science B.V. All rights reserved.