The oligodeoxyribonucleotides bearing 2, 2′-anhydro-β-d-arabinofuranosyluracil derivatives were synthesized and the modified residue was converted to β-d- arabinofuranosyluracil derivatives or β-d-arabinofuranosylisocytosine derivatives by post- synthetic modification method. The melting profiles of their ODNs with complementary DNA were studied.