The regioselectivity of the [3+2] cycloaddition reactions between trans-β-nitrostyrene and C,N-diarylnitryle imine analogues as three atom components (TACs) has been studied with the use of Conceptual Density Functional Theory in the framework of Molecular Electron density Theory. Global and local reactivity indices were determined. Presented quantum-chemical computations showed that, for the reaction of nitroalkene with diphenylnitryle imine, the most favourable reaction path is determined by the nucleophilic attack of C3 carbon atom of TAC on an electrophilic C_α carbon atom of nitroalkene. Therefore, the creation of 1,3,4-triphenyl-5-nitro-Δ²-pyrazoline, according to channel B, is more probable. Similarly, to presented conclusion, for reactions of nitroalkene with nitryle imines containing ED group at para position of the phenyl ring also the most favourable reaction paths run through channel B leading to 1,3,4-triphenyl-5-nitro-Δ²-pyrazolines. In turn, reactions of nitroalkene with nitryle imines containing EW group at para position of the phenyl ring have the opposite preference and the most favourable reaction paths is channel A leading to 1,3,5-triphenyl-4-nitro-Δ²-pyrazolines.