In the field of linear elastic fracture mechanics, the stress intensity factor approach has been widely accepted as a valid means for predicting the behavior of a material in the presence of a crack or flaw. To optimize their dimension and to ensure their safety in service, a practical study of the strength under centrifugal force is important. In this paper, it is investigated that the stress intensity factors KI and KII on the rotating elliptic disks having outside cracks by means of combining the photoelastic freezing method and the caustics method. Stress intensity factors KI and KII were determined by using two experimental methods, as a function of ellipticity of the elliptic disk (R2/R1=0.9, 0.8, 0.7, 0.6, 0.5) and at two different velocities. The results of these experimental methods was nearly agreement, and attracted the interest.