Abstract: In this paper the S-electron densities of C and H atoms of N -CH₂-Rradicals in the nitrogen heterocyclic ring compounds have been calculated with EHMO program. The S_C·S_H is equal to 1.172 +0.006 for the series of pyridine salts and 1.162+0.015 for the series of carbazole. Experiments showed that the NMR coupling constants ¹J_CH are 144 +2Hz and 135 +2Hz respectively for the two series. Comparing the calculated rezults with the experimental data it can be explained that the ¹J_CH are not varied with exchanging of substituted radicals.