Based on qualitatively analyzing influence factors, the model for predicting the height of tidal bore at Yanguan is established by using BP neural network. The comparison of the simulated results with the observeddata shows that the model has good generalization ability. In combination with the theory of orthogonal experiment design, the major affecting factors such as tide, runoff and river topography are quantitatively analyzed. It is found that the height of tidal bore is positively related to the tide, and negatively related to the river topography. The height of tidal bore is positively related to the runoff when the discharge is less than 7 000 m3/s. However they are negativecorrelation relationship if the discharge is greater than 7 000 m3/s.