Continental shelf islands are contributors of terrestrial sediment supply to shelf regions, and the sediment flux from these islands shall be quantified. We calculated the sediment flux of continental shelf islands in the southeastern China using two empirical equations under two preconditions. The first, the sediment load/yield of the islands has the same pattern as the adjacent small, mountainous rivers along the coastline; and the second, each of the islands was treated as a single catchment. The results show that the sediment supply from these islands reached an order of magnitude of 1 Mt / a , which is comparable to the supply from the local smaller rivers. A sensitivity analysis indicates that this value represents the lower limit of estimate; if the accurate amount of sub-catchments of any island is considered, then this value will be enhanced slightly. This study demonstrates that the sediment supply from continental shelf islands to oceans is an important factor affecting the regional sedimentation and, therefore, should be paid with attention.