Two types of the plasmid were prepared. One was the circular plasmid having the inverted repeat of two units of the telomeric repeat unit (5’-TTAGGGTCAACA) for Aspergillus oryzae and the autonomous replicating sequence AMA1 for Aspergillus nidulans. The other was the linear plasmid having two telomere units with both ends and AMA1 inside. Both plasmids were introduced in A. oryzae. The resulting transformants using the circular plasmid appeared to harbor the original circular one. The transformants with the linear plasmid harbored the circular one which was derived from the linear one by self-circularization. Therefore the two telomeric units were not recognized as the terminus of the DNA. More telomeric repeat units might be necessary for construction of the linear vector using the telomeric sequence of A. oryzae.