Unnatural "L-DNA" containing 2'-deoxy-L-ribose backbone instead of natural 2'-deoxy-D-ribose was synthesized and evaluated by (1)H NMR, CD spectra. Proton ((1)H) NMR spectra of natural DNA (D-TpT) and L-DNA (L-TpT) are fully consistent with each other. In CD spectra, however, spectrum of L-TpT was reversed, relative to that of D-TpT. These results indicate that L-TpT is an isomer with a mirror image configuration of D-TpT. In summary, we have synthesized enantiomeric L-DNA, and the L-DNA would be materials for nanodevices and tools for exploring why the D-isomer of DNA molecules was selected as a bio-molecule.