A circular notched round bar specimen produces multi-axial stress field when uni-axial stress is applied in the axial direction. This stress field is produced in practical component structure. Therefore the characterization of creep crack growth rate under this condition is important for practical use. In this paper, developed 12Cr ferritic heat resistant steel was noticed. High temperature creep crack growth tests were conducted for a circular notched specimen for 12Cr ferritic heat resistant steel. And in order to investigate multi-axial stress state of a circular notched specimen, we have conducted 3D FEM analysis. The stress multiaxiality of a circular notched specimen increased as compare with that of CT specimen. Q* parameter which predicts creep crack growth rate is derived for this specimen. On the bases of this Q* parameter, the algorithm of predicting the life of creep growth is proposed.