X-ray K-absorption spectra of some cobalt(l1) complexes of newly synthesized mannich bases of biological interest have been studied using Seifert X-ray generator and Cauchois type bent crystal X-ray spectrograph of 0.4 m radius. The observed X-ray parameters, e.g. chemical shift, shift of principal absorption maximum, edge-width, effective nuclear charge and percentage covalency have been used to explain the structure of the complexes, and these parameters have also been correlated with earlier chemical studies.