Air parcel backward trajectories of long-range transport at six coastal cities, Dalian, Qingdao,Shanghai, Fuzhou,Xiamen and Guangzhou,are discussed.The transport layer is assumed to be 1500 m high, the trajectories during January, April, July and October 1985,are computed. The trajectory analysis shows that: (1 )The backward trajectories of air parcel are related to weather situations and seasons,and however the backward trajectories between the coastal cities in the North and in the South are different.(2)The transport-distances (the backward trajectory of 72 h) of the coastal cities in the North are farther than that in the South.