Abstract: A new Cellular automaton model for the bicatalytic CO＋O2 surface reaction is introduced by means of building oriented two-pointed "superstructure" in lattice.Reactions can only happen in superstructures. 　　We use reaction probability as variable to control reactions in superstructures.We use rate-per-α as variable to determine the optimum configuration for a series of α′s occupation from 1/9 to 8/9(3×3 lattice as unit) and from 1/16 to 15/16(4×4 lattice as unit).

Key words: Cellular automaton, Bicatalyst, Simulation, Optimum configuration