Our results of dynamic simulation for the dust tail formation of the comet C/1995 O1 (Hale—Bopp) are presented. To simulate the dust tail, the trajectories of 2·10⁶ dust particles were traced. The sizes, ejection moments, outflow directions and velocities of the dust particles were defined by the Monte Carlo algorithm. The obtained three-dimensional tail was projected on the sky plane to compare it with the observed images. The brightness distribution in the comet tail was fitted to similar model parameters for three different dates. According to our model experiments the observed tails could be formed by particles with sizes from 0.3 to 8.0 µm, ejection velocities from 0.155 to 0.670 km/s and power index of the exponential size distribution from –3.6 to –3.7. It is shown that taking into account fragmentation processes of the particles results in a noticeable improvement of the simulation results.