Before revision:  An algorithm for stochastically approximating the high-molecular reactions with a set of bi-molecular ones, involving at most two reactants, is presented.
After revision:  An algorithm for stochastically approximating the high-molecular reactions with a set of bi-molecular ones, involving at most two reactants, called bi-molecular reactions, are experimentally feasible. To bridge the gap, in this paper we put forward an algorithm for systematically approximating arbitrary higher-molecular reactions with bi-molecular ones, while preserving the underlying stochastic dynamics.