Abstract: By extensively reading,contrasting and analyzing a variety of references of the formation and classification methods for microbial carbonate,it is found that some kinds of microbes,such as cyanobacteria,sulphate-reducing bacteria,methanogenic bacteria and so on,in theirmetabolic activities can change physiochemical conditions of microenvironment,which results in the precipitation of Ca²⁺ and Mg²⁺,microbes also can catch and adhere allochthonous grains and can be self-calcified,all activities above finally cause the formation of microbial carbonate rocks.On the basis of the formation mechanism and macrofab rics microbial carbonate can be classified in to stromatolite,throm bolite,dendrolite and leiolite,which preliminarily established classification system and was agreat progress in carbonate sedimentology.In addition,Oncolite and Laminite also with special macrofabrics and important geological significance should belong to microbial carbonates in parallel with stromatolite,thrombolite,dendrolite and leiolite.