In this study,three kinds of individual coking coals with different ranks were selected,i.e.gas coal,fat coal and main coking coal,which are carbonized into coke at the end of coking temperature 950 ℃.The pore structure parameters of coke were measured by micrograph analysis.The pyrolysis volatilization process of coking coal was measured by thermogravimetric analysis and the pyrolysis softening flow process of coking coal was measured by Gieseler plasticizer.The results show that the interaction between volatilization and softening flow of coking coal determines different microporous structures of the coke.