Aminoacylation of tRNA was attempted through formation of tRNA/DNA/aa-PNA (N-aminoacylated peptide nucleic acid) ternary hybrid. A 23-mer DNA, that is complementary to a 3'-terminal of tRNA and to a 9-mer PNA carrying an amino acid unit, was designed to achieve close proximity between the amino acid and the 3'-OH group of tRNA. The aminoacylation was carried out in a buffer solution containing imidazole. The aminoacylation was detected by nuclease S1 treatment followed by HPLC and MALDI-TOF MS. This novel methodology will open a way for easy and versatile aminoacylation of nonnatural amino acids onto specific tRNAs.