Abstract: There are distinct differences in slab thickness,casting speed,cast structure and on-line continu- ous rolling between thin slab casting and conventional process.The thin slab process has some advantages of stronger cooling strength,shorter product line and lower consuming.In the meantime,it also has some disad- vantages of not so good surface quality and small range adaptability in production.In recent years,the technol- ogy of thin slab continuous casting and rolling has been developed very much in China and more than ten prod- uct lines have been built.But there is different estimating about this process.In this paper,it is analyzed about the advantages and disadvantages of microstructure,precipitation of compound and adaptability of thin slab in order to objectively and practically evaluating the process of thin slab continuous casting and rolling.