Comment on a mechanism of dynamical breaking of supersymmetry

We re-examine the so-called Nambu-Jona-Lasinio mechanism suggested by Song, Xu and Chin in breaking the supersymmetry in the Wess-Zumino model and show that this mechanism cannot be justified without assuming special effects between fermions. The fermion condensation suggested by them corresponds to an unstable vacuum configuration. As a result, there is no fermion condensation and no supersymmetry breaking in the model discussed by them.