Simulation of the Liesegang pattern formation in low concentration gradient is presented using concentration perturbation in a deterministic model. The precipitation process is based on ion-product supersaturation theory (Ostwald's model). In the classical experiments with high initial concentration gradients, appearance time and locations of the band formation are well reproducible. Decreasing initial concentration gradients results in a more stochastic pattern structure; this means that the reproducibility of the experiments becomes worse. The presented model and the results of the simulations exhibit the same trend, which were demonstrated and investigated experimentally by Kai [S. Kai, S. C. Muller, and J. Ross, J. Phys. Chem. 87, 806 (1983)] and Kai and Muller [S. Kai and S. C. Muller, Sci. Form 1, 9 (1985)]. (C) 2004 American Institute of Physics.