The pattern recognition methods and a four-parameter model, based on extension of Miedema’s cellular model of alloy phases, are used to study the regularities of formation of ternary com- pounds between one transition element (T) and two non-transition elements (N, N’) (T-N-N’ system). The influences of φ (electronegativity), (valence electron density in Wagner-Seitz cell), .R(Pauling’s metallic radii) and Z (number of valence electrons in atom) on the formation of the ternary intermetallic compounds were investigated. The pattern recognition methods and a four-parameter model, based on extension of Miedema’s cellular model of alloy phases, are used to study the regularities of formation of ternary com- pounds between one transition element (T) and two non-transition elements (N The influences of φ (electronegativity), (valence electron density in Wagner-Seitz cell), .R (Pauling’s metallic radii) and Z (number of valence electrons in atom) on the formation of the ternary intermetallic compounds were investigated.