A three-dimentional thermal elastoplastic contact FE analysis model of solidifiedshell in moulds for continuous casting of thin slabs is set up, based on the known geometry of theshell and the temperature distribution in the shell. We in turn obtain the stress and Strain distributions of the solidified shells formed in lSP and CSP moulds,the gap distributions between the Shellsand the mould walls,as well as the curves of cracking index [1] in the shells,which provides afoundation for the design and control of technical parameturs for continuous casting of thin slabs.