We present in here the study by means of electron energy loss spectroscopy (EELS) of several rutile based oxides, having in common the presence of octahedrally oxygen coordinated chromium, [Cr-O6], in three different formal oxidation states: Cr4+ in CrO2, a regular rutile; Cr3+ in CrOOH, a H bonded orthorrombic distorted rutile and in CrTaO4, a metal disordered rutile and Cr2+ in CrTa2O6 an ordered trirutile structure. A linear relationship is observed between the formal oxidation state of chromium in all these rutile oxides and the separation between the Cr-L2,3 and O-K energy loss peaks.