A discussion of the origin of the observed matter‐antimatter asymmetry of the universe is presented in the context of the standard cosmological model. Except in the case of the minimal SU(5) theory, it is possible that grandunified theories predict the right order of magnitude for the ratio of baryon to photon number. The question of CP violation is addressed in detail and it is shown that, tied up with symmetry nonrestorationat high temperature, the soft CP violation does remain atT?1015GeV as to lead to the creation of baryon asymmetry in the very early universe.