The effect of chemical combination on the X-ray K absorption edge of cobalt complexes has been investigated using a 400 mm radius bent crystal spectrograph of Cauchois type. Monodentate and bidentate cobalt complexes of octahedral coordination were investigated. It has been noted that in these cobalt complexes the shift is towards the high energy side. From the energy shift the effective charge on cobalt atom in different complexes has been calculated.