Abstract: The formation of hollow structure and its characteristics of typhoon "Matmo" were analyzed based on diagnostic analysis methods including the circulation situation,vertical structure of typhoon,water vapor transport and the effect of intrusion of the cold air.The conventional meteorological data,NCEP (National Centers for Environmental Prediction) reanalysis and FY-2 cloud data were used.The results show that the terrain,such as Taiwan Island,the mountains along the coast of Fujian province and Wuyi Mountains,is the main reason to influence the change of intensity and structure of typhoon "Matmo".The vorticity and divergence fields at upper and low layers,water vapor flux transport,the intrusion of the ground cold and dry air among others contribute to the formation of the "hollow" phenomenon of "Matmo".Compared with the other typhoons,it indicates that even though the tracks and influencing regions are similar,their structures are significantly different.This suggests that the structure change of landing typhoons is very complicated.