Abstract: For a better solution of the congestion shifting problem in Urban Traffic Flow Guidance System (UTFGS),this paper analyzes the root causes of the congestion shifting problem and develops a constrained K-shortest paths algorithm suitable for the travelers.With the realization in the basis of MapX Control,the actual effect of this algorithm is tested with the micro simulation tool VISSIM. Conclusions could be drawn as follows,the constrained K-shortest paths algorithm can efficiently prevent the congestion shifting problem,so that both the travelers and the whole system could benefit a lot from this.