The effects of distribution of deoxidized product by Mg and dissolved Mg content on abnormal grain growth had been carried out in Fe-0.2wt%C-0.02wt%P alloys maintained at 1673 K for 60 minutes. Homogeneous distribution of deoxidized product during solidification was strongly depended on the cooling rate, and degree of that was conformed by homogeneous distribution degree(H.D.D.) defined by author. In the cooling rate of 40 K/min, the distribution of deoxidized product was almost homogeneous. A_(max)/A_(mean), which is widely used to represent the degree of abnormality, was depended more on the content of dissolved Mg than on the volume fraction of deoxidized product in the condition of 40 K/min cooling rate. And. A_(max)/A_(mean) was also deeply related with the aspect ratio (the ratio of the longest length of grain to the longest width perpendicular to the longest length)