Reef rocks are classified into primary ones and secondary ones. Primary reef rocks include framestone, bafflestone, prebafflestone, bindstone and coverstone. The framestone, baffle-stone, prebafflestone are called by a joint name erectistones. Secondary reef rocks contain secondary components, i. e. , grains formed from reefbuilders or reef rocks, and thus are classified into biosubstones having reef builder's fragments or skeletons, and reefsubstones having fragments of reef rocks. Biosubstones are divided into biorudstones whose secondary components are in contact and biofloated rocks whose secondary components are floated. The biorudstones whose secondary components are overturned whole skeletons rather than fragments are named bioly-stones. Reefsubstones are divided into reefrudstones whose secondary components are in contact and reefloated rocks whose secondary components are floated. Biorudstones are further classified into biobouldstone, biocobstone, biogranustone and biosandstone according to the size of the secondary components. Reeffrudstones are further classified into reefbouldstone, reefcobstone, reef-granustone and reefsandstone according to the size of the secondary components. Biofloated rocks are divided into biobouldfloated, biocobfloated, biogranufloated and biosandfloated rocks. The biofloated rocks whose secondary components are whole skeletons rather than fragments are named biolyfloated rocks. Reefloated rocks are divided into reefbouldfloated, reefbobfloated, reefgranufloated and reefsandfloated rocks.