The magnetic intermediates in the Ziegler-Natta type catalytic systems for dimerization, oligomerization of lower olefins, in related systems, based on a complex of zero valent nickel in combination with β-diketones, azo, azomethine compounds are studied by electron magnetic resonance (EMR). Para-, superpara/ferromagnetic intermediate complexes, particles in these systems, the products of their reactions with ethylene, propylene are identified, their role as catalytically active in these reactions is discussed. The spectra of magnetic EMR intermediates, most of which were obtained for the first time and is absent in the world literature are given