Abstract: In order to determine the occurrence of traffic conflict more accurately, a critical conflict area model base on vehicle type was proposed. The model improved the previous traffic conflict model and took the impact of the vehicle size and braking process into consideration. And the radius of conflict of different vehicle type was analyzed to prove the importance for the influence of vehicle type on traffic conflict discrimination. Finally, the influence of speed and vehicle position was analyzed; and the shape of conflict area for specified vehicle speed could be observed in the model. The new proposed model improved high accuracy of conflict discriminant. The model mentioned above was analyzed in the views of quantitative and qualitative method.