Abstract We discuss the properties of supernova matter equation of state (EOS) including hyperons, and the emergence of hyperons in dynamical core-collapse processes. The recently tabulated EOS including hyperons is based on an SU f (3) extended relativistic mean field (RMF) model, in which the coupling constants of hyperons with scalar mesons are determined to fit the hyperon potential depths in nuclear matter, (U Σ , U Ξ ) = (+30MeV, −15 MeV), which are suggested from recent analyses of hyperon production reactions. Hyperon effects are found to be small in the core-collapse and bounce stages, but abundant hyperons appear when the temperature becomes high during the black hole formation and promote earlier collapse of the accreting proto-neutron star. The maximum mass of hot proto-neutron star is discussed, and it gives a rough estimate of the critical mass of the accreting proto-neutron star, at which the proto-neutron star re-collapses to a black hole
