Abstract: For the complex reactions (steady state, isothermal，constant volume and one inflow), this paper extends the attainable region partition method of reactor network synthesis from the concentration space to the instantaneous selectivity (S)-unreacted fraction of key reactant (x) space and establishes the models of two reactor networks basic constituent elements (PFR and CSTR) for waste minimization according to the properties of two important curves (maximum selectivity curve: dS/dx=0; maximum yield curve: S=0) within the partition method of reactor network synthesis and applies them to the simulation of the optimal reactor networks structure obtained by the partition method for several Van de Vusse reaction examples. The computation results are consistent with those reported in the literatures, which indicates the proposed method is to some extent convenient and practical.