Computer simulation of incoherent exciton migration in a quasi-one-dimensional (q-1-D) lattice with randomly distributed traps has been performed. The model assumes both efficient and inefficient exciton trapping. Simulative curves are fitted to the experimental exciton decay curves in q-1-D antiferromagnetic crystals CsMnCl3 . 2H(2)O (CMC) doped with copper ions (1% and 0.1%). The hopping rate along a chain (W) and trapping rate (U) have been defined. These rates are compared with those obtained from fitting the theoretical curves (1-D model of exciton migration) to the experimental ones.