Abstract: Calcium carbonate is widely used in many industries，such as plastic，paper，dope，rubber，commodity chemicals，medicine，food，and feed etc..It can be classified as heavy calcium carbonate（GCC）and light calcium carbonate (PCC）according to processing methods.And it can be classified  as ordinary calcium carbonate and active calcium carbonate according to modification or not.It also can be classified as special calcium carbonates according to their applications.For the convenience of industry management，statistic and users，it is suggested to be classified two kinds as heavy calcium carbonate and light calcium carbonate according to processing methods and average particle size.Light calcium carbonate is classified as three kinds i.e.light calcium carbonate（＞2.0 μm），ultrafine calcium carbonate（0.1～2.0 μm） and nano-sized calcium carbonate（≤0.1 μm）.Each kind is further divided into active，ordinary and special products etc..Heavy calcium carbonate is classified as three kinds i.e.heavy calcium carbonate（＞10 μm），microsized heavy calcium carbonate（2.0～10 μm）and ultrafine heavy calcium carbonate（0.1～2.0 μm）.Each kind is further divided into active，ordinary and special products etc..Physical and chemical indexes of all kinds of calcium carbonate must accord with the standard of the country，industry and enterprises respectively.