Abstract: The thetial solidification shell as research object was studied. Some grooves were curved vertically in the mould. Mathematical model was established. The temperature fields and stress fields of initial solidification shell in the mould of smooth and groove were calculated,the difference between the tWo condition was analyzed and effect to dritial solidiflcation process caused by model of grooves was stUdied.The results show that conduct heat of slab can be Anproved clearly and stress can be reduced and distributed eveuly by the mould with groove in surface.