Abstract:A statistical analysis of the characteristic of typhoon track deflection relative to the steering flow in East China is conducted with the CMA tropical cyclone best track dataset and the ECMWF ERA5 reanalysis data from 1950 to 2022. The results show that 85.2% of 54 landfall typhoons’ tracks deviate to the left of the steering flow at the time of landfall, and the coastal terrain can produce an averaged deflection angle of about 6°-7° from the steering flow. The deflection angle between the typhoon tracks and the steering flow at the landfall time has a good correspondence with the thermal asymmetry parameters. Generally, a cyclone with a nearly thermal symmetric structure at the time of landfall corresponds to a smaller deflection angle, while the obvious thermal asymmetric structure would increase the possibility of a large deflection angle. The coastal terrain is prone to triggering asymmetric convection on the left side of the cyclone near the landfall, affecting the distribution of thermal structure and causing the typhoon tracks to deviate to the left of the steering flow. The development of convection on the left side of the cyclone can sometimes decrease the thermal asymmetry parameter at the time of landfall. So, more attention should be paid to the evolution of thermal asymmetry near the landfall instead of the asymmetry itself for more accurate prediction of typhoon track deflection.