Based on sequences data, TTV have a partial Rep protein motifs found among Circoviridae and the conserved region of parvoviral nonstructural polypeptides (NS)-1 genes, however we could not perform phylogenetic analyses among TTV and other viruses because of few similar sequences. Putative ORF2 among G2 and G4 encoded 49 aa because of in-frame stop codon, although that of G1 encoded 202 aa. Just down-stream of the stop codon, another putative new ORF(ORF3) were found around 150 aa. A phylogenetic analysis, using the ORF1 sequences of 93 TTV obtained from various geographical areas, indicated that the virus could be classified into six different genotypes. Further studies using more than 350 isolates obtained from DDBJ showed at least nine genotypes.