Abstract: The causation of coastal aeolian sand and its depositional characteristics in coast areas in China is described in the study. It is deemed in the paper that the sand dunes and aeolian sand deposits along coasts in China extend all over sandy coasts in different degree. The process, scale and developmental trend of coastal aeolian sand deposits differs in every part of coasts because of the difference of relation ship between the trend of coastline and the monsoon effects. The sand dunes can be formed only under the aeolian sand effect in the areas where the trend of coastline and superior northwest wind areslating-crisscross and where the sea tides are weak and the rising water is less. So far, only megadunes are sufficient in sand materials supply. Most part of coasts, however, are insufficient in sand materials supply on seabed at present, thereby just a thick sand deposit may be formed along coast. The occurance of aeolian sand along coast in China is not very long. It is explained in the study that the climate on the earth varied obviously in the later recent epoch and from then the air current is being risen and aeolian sand is being gradually developed. Thus the original landscapes of coast sand mounds and lagoon deposit is enormously changed.