Simulation study has been carried out to analyze the air flow supplying from the heat pump system inside the tollgate booth by using the Phoenix computer simulation program. Through this simulation analysis we can find the problem of present tollgate booth in terms of air flow and recommend an improved model also simulate this model. Final results as follows; It was turned out that the fresh air conditioning is not provided to the worker effectively due to the improper location of inlet and outlet in the present tollgate booth in addition to that the air curtain system applied in the booth lowered air circulation from outside. The improved model was suggested first to increase the air curtain effect by downsizing the window and by installation of the air curtain suction line to reduce the induced outdoor air second to supply the fresh air to the worker directly by relocation of the inlet and outlet of supplying air. With these improved modifications better results have been reached in terms of air flow inside the booth. Next through the air flow simulation of outside booth the contaminated outdoor air has been easuily infiltrating into the booth through the window because of its rectangle shape. Stream like shape of booth has been proposed through the computer simulation as an alternative shape of tollgate booth for a new design.