An abnormal grain growth mechanism in Fe-3%Si steel was investigated. During heat treatment, Goss grains started to grow abnormally at 1050degreesC, and their abnormal growth was almost completed remaining numerous island grains or grain clusters at 1100degreesC. Besides, abnormally growing Goss grains display some distinctive grain structures. These structures show the penetration of the Goss grain into the grain boundary between the two neighboring grains. The analyses of the island grain and the penetrated grain structure indicate that solid-state wetting is an important growth mode of Goss grains and appears to be closely related to the mechanism of abnormal grain growth.