Abstract: The traditional static guidance algorithm can't suit the dynamic situation.Genetic algorithm(GA) and geographical information system(GIS) were adopted to seek the vehicle driving route guidance algorithm based on the real-time traffic information.A dynamic route guidance algorithm based on GA and GIS is proposed on the basis that the time-dependent dynamic traffic network was built.In order to realize the algorithm,the special function of fitness,the arithmetic operators of selection,crossover and mutation,which accord with the characteristics of dynamic traffic network,were designed.The high efficiency of this algorithm was proved by an experiment.