The paper discusses problems of a special variant of nuclear magnetic resonance, namely, the resonance observed in compounds with a magnetic order. It is shown that this effect acquires additional differences from the conventional case if it is registered in nanostructured magnetic materials, for which a number of estimates are obtained. The analysis of changes in the enhancement coefficient of the exciting radio frequency field for objects with uniaxial magnetic anisotropy, to which particles of dispersed substances tend to pass with their sizes decrease, is carried out. Relaxation processes and possible mechanisms for changing of the relaxation times of nuclear spin system are discussed. The specificity of this type of resonance is demonstrated by the example of a nanomaterial based on magnetite, used as a precursor for the preparing of ferrofluids. The difference in the parameters of nuclear magnetic resonance signals in bulk and nanostructured samples is valuated and the resulting special requirements for experimental equipment are determined.