Abstract: Before the Mai-U or the plume rain season, the cyclones of Eastern China mostly travel far south of the Yangtze river in a direction from SW to NE. The distribution of rai fall is very even on both sides of the track. During the Mai-U period, the tracks of the cyclones move slightly northwards, but still keep to the south of the Yangtze. In this case the distribution of rainfall is asymmetrical and the rainfall belts are usually situated in the left hand quarters of the cyclones, or in the northern side of the tracks. This uneven distribution of rainfall is very striking as cn,npared with that of the cyclones before the Mai-U period. The rainfall belt is about 300 km in wideth The cyclones of North China are mostly rainless, except when they come near to the saa coast. But in their journey eastwards, after having travelled vast expanse of the Yellow Sea, they always cause heavy rain Kores and tha amount is even comparable with that of the cyclones of the Yangtze Valley.The rainafll belt is sometimes situated to the south and sometimes to the north of the track.