Abstract: Three-phase intersection capacity calculation method was studied. Based on the stop-line method, the calculation method for the right-turn lane was improved, as well as the left-turn and straight-turn line while there is no dedicated signal phase for left-turn. Further, the improved model was proposed to calculate the three-phase intersection capacity. Then, using the data of the actual intersection, the capacity of the junction was calculated based on the stop-line method and the improved model, respectively. The results show that the improved model can effectively improve the stop-line methods deficiencies at calculating the three-phase intersection capacity. The calculation results are closer to the measured data, and are not affected by the actual survey data.