A four-dimensional vector formalism is derived for a phenomenological description of neutral K-meson decay. Probability amplitude equations for K₀- and K₀-meson states are represented as an 'energetic-space' Lorentz invariant. In contrast to the well known superweak interaction model, the main parameters of K₀-meson decay are described by two real effective vectors. The approach suggested reveals a simple connection between the phenomenological constants of the weak interaction and such observable quantities as the K_S- and K_L-meson lifetimes. K_L-K_S mass difference and the value of charge asymmetry in semileptonic decays. The analogy of master equations with the quadric Dirac equation is pointed out. A four-component (bispinor) description of the K_S- and K_L-meson states is constructed.