Use is made of the branching ratio, lifetime, and asymmetries of the angular distributions in Σ-decays to show that the selection rule |ΔI| = ½ is consistent in the decays of Σ-hyperons as well as in the Λ-decays. The invariance under time reversal is assumed, and the asymmetry parameters, the average degrees of polarization of Σ and the ratios of the coupling constants are obtained.