The computational models for the analysis of heat transfer and related linear contraction of slab casting have been developed for the continuous casting process. The temperature profile, solidification progress and the linear contraction in the thickness direction have been revealed accordingly. Based on the in-situ casting condition of 304 stainless steel, it is shown that the slab linear contraction develops slowly at the initial period of the secondary cooling, but shows quick development at the final stage of the cooling zone while approaching the crater end. The remarkable differences of the total contraction amount and linear contraction rate have been observed for slab under its varied casting speed. The contribution from the thickness of slabs, however, is observed only at the later stage of the slab solidification. There is no remarkable variation of the slab contraction behavior for different casting temperature. Moreover, uneven contraction phenomenon has been revealed in the wide face of the slab casting, in which larger linear contraction is produced away from the centre with maximum at corners. And the different linear contractions in the wide face of the slab constitute the roller gap window of the casting steel.