The eelgrass in Miyako Bay was greatly damaged by the tsunami. For future restoration of the eelgrass, we collected sediments from 110 stations in the bay and analyzed particle-size distribution and chemical composition in 2012 and 2013. The distribution of eelgrass was also measured at the same stations. The sediments on the south and west coast were suitable for eelgrass. On the other hand, the sediments on the east coast were coarser. The chemical composition indicated that we could not expect the supply of sand from the main river to the east coast. We estimated that the restoration of eelgrass on the east coast would be slower than on the west and south coast.