A simplified E.Coli foraging optimization algorithm based on the chemotactic behavior of E.Coli is presented in this paper for the parameter estimation problem of nonlinear system model (NSM). The simplified E.Coli algorithm includes a tumbling operator, a swimming operator, the optimal position of individual E.Coli and the location of all E.Coli swarm are adopted to update the locations of swarm (tracing operator of optimal values). The effectiveness of the proposed simplified E.Coli foraging optimization ...