The evolution of islands in the Xisha Islands is closely related to the growth of coral reefs. The coral reefs in the studied area can be put into three groups:1. Complex atolls: They consist of several atolls with a lagoon at the center. Three complex atolls named Yongle, Xuande, Xuandedong (Eastern Xuande) are recognizable.2. Individual atolls: We have found five small atolls grown up on separated foundations with small lagoons at the center.3. Platform reefs: Those are the reefs with flat top. In this group two islands named Jinyin and Zhongjian are included.There are 31 islands in the area, 27 of them are investigated by the authors. Based on the statistic method it can be seen that all islands are grown up on reef flats with the axes parallel to the latters.No relation between the distribution of the islands and the size of reef flats has been found. However, most of the islands occur on the lee side of the prevalent wind, this means that the wind has played a great role in the evolution of islands The evolution of islands in the Xisha Islands is closely related to the growth of coral reefs. The coral reefs in the study area can be put into three groups: 1. Complex atolls: They consist of several atolls with a lagoon at the center. Three complex atolls named recognizable.2. Individual atolls: We have found five small atolls grown up on separated foundations with small lagoons at the center.3. Platform reefs: Those are the reefs with flat top In this group two islands named Jinyin and Zhongjian are included.There are 31 islands in the area, 27 of them are investigated by the authors. Based on the statistic method it can be seen that all islands are grown up on reef flats with the axes parallel to the latters.No relation between the distribution of the islands and the size of reef flats has been found. However, most of the islands occur on the lee side of the prevalent wind, this means that the wind has played a great role in the ev olution of islands