The authors have found that a ductile crack initiation for compressively prestrained steel can be evaluated quantitatively via a limit curve of ductile crack initiation, which is presented by stress triaxiality-critical equivalent plastic strain relationship. In this research, validity of the limit curve approach, with which ductile crack initiation for compressively prestrained steel is predicted, was examined and stress-based quantitative evaluation of brittle fracture initiation for the compressively prestrained steel was investigated through experiments and numerical analysis. In this investigation, validity of the limit curve approach was confirmed and it is found that brittle fracture occurs with the critical cleavage fracture stress depending on compressive prestrain.