Abstract: Two-stage fuzzy controller,which is easy to acquire fuzzy rules and can greatly decrease the number of fuzzy rules,is very suitable to complex urban intersection control.But it still presents a difficulty for deciding all the membership functions correctly only by human experience.There for,to solve this problem, a technique using genetic algorithm to modify its fuzzy membership functions is proposed.For a single urban intersection with four-phase,much simulation is processed.Simulation result shows that this method can effectively decrease the average delaying time in the intersection and is superior to the conventional method.