Based on the equilibrium stage model in the separation process of the boron isotopes by chemical exchange reaction and distillation, the operation policy on start-up time was mathematically simulated by use of SIMULINK. The simulated data of dynamic model showed good agreement with the experiment data. The optimum operation policy was predicted by the proposed model. Compared with other operation policies, the cascade feed policy was suitable for high-purity boron isotopes separation by chemical exchange reaction production and distillation. (c) 2007 Elsevier B.V. All fights reserved.