Based on the infrared satellite images of MTSAT2 and NCEP/NCAR reanalysis data,this paper studies the cause of abnormal track of tropical cyclone Meranti(2010).The track of Meranti consists of three stages:the westward moving phase,the rotating phase and the northward moving phase.Results show that the environmental steering flow plays a key role in the westward moving phase and the northward moving phase,and the asymmetric structure of Meranti also has a certain influence,whereas the influence of asymmetric convection system is weak.The asymmetric convection system plays a main role in the rotating phase,including interaction of Meranti with two neighboring meso-scale vortices,the Meranti escaping northeastward in the binary vortex process and so on.It also shows that the fractal dimension of Meranti border line in the rotating phase is obviously different from that in the westward or northward moving phase,which is significantly lower with notable fluctuations.