In this work, we are interested in the geometrical, energetical and spectroscopic characterization of hydrogen bonding interactions in the family of benzimidazolyl-chalcones(BZC) substituted molecules. The BZC exhibit wide ranges of properties, and particularly, show important nematicidal activity properties. Four molecules from the family of BZC, with various activity, have been selected for this work, including (2E)-1-(1H-benzimidazol-2-yl)-3- phenylprop-2-en-1-one (BZC-1, LC100= 0,002 μg/ml), (2E)-1-(1H-benzimidazol-2-yl)-3-(4-bromophenyl)prop-2-en- 1-one (BZC-2, LC100= 424,5 mcg/ml), (2E)-1-(1H-benzimidazol-2-yl)-3-(4-fluorophenyl) prop-2-en-1-one (BZC-3, LC100 =12,0 μg/ml), and(2E)-1-(1H-benzimidazol-2-yl)-3-(2-furyl) prop-2-en-1-one (BZC-4, LC100= 2,87 μg/ml). The activity measuring is based on the lethal concentration for one hundred larvae (LC100)population. The geometrical, energetical and spectroscopic parameters of hydrogen bonds on each heteroatom (named H bond complexes) of these molecules have been determined by quantum chemical methods, particularly at HF/6- 311+G(d,p) and MPW1PW91/6-311+G(d,p)theories levels. Choosing Hartree-Fock (HF) and Density Functional Theory methods(DFT/MPW1PW91) allowed accuracy results with relatively less time consuming. Furthermore. Taking into account basis set superposition error(BSSE), gives a quantitative results. Finally, sp2nitrogen atom has been identified as the preferential hydrogen bonding site in the four studied benzimidazolyl-chalcones, even if carbonyl oxygen cannot be neglected