Perdeutero[70]fullerane, C70D38 and the hydrogenated analogous C70H38 have been synthesized using nascent deuterium or hydrogen generated by the action of DCl or HCl on Zn dust in toluene or benzene solvents. The FT-IR spectra of C70D38 and C70H38 have been studied. A better oxidation stability of C70D38 has been observed by FT-IR spectroscopy in comparison to that of C70H38. Similarly, thermogravimetric analysis (TGA) and differential thermal analysis (DTA) have revealed a better thermal stability of the deuterated molecule in comparison to its hydrogenated analogous. The results have been interpreted in terms of isotope effect. Oxidized fulleranes are soluble in concentrated sulphuric acid where they undergo a partial elimination reaction producing fullerenes with a lower degree of hydrogen content.