Abstract: The application of Threshold based Antnet Algorithm in traffic guidancewas presented. Simulation was conducted to evaluate the effect of the algorithm in the dynamic traffic system. Prior information for the traffic network was used as threshold, for instance, good travel time between nodes. The algorithm eliminated certain routes according to those preset values. Besides, "check ants" were introduced to periodically check the assumptions and save the routes. Optimization performance of the presented algorithm was certified with dynamic traffic environment using R software. The simulation shows a 9.57% reduction in the average travel time of ants launched in presented algorithm compared with the classic algorithm. Threshold based traffic guidance scheme can meet real time and high efficiency demand of city traffic.